Visual Basic IMPORTANT QUESTIONS

1. How do you register a component? Expected answer: Compiling the component, running REGSVR32 MyDLL.dll
2. Name and explain the different compatibility types when creating a COM component. Expected answer: No Compatibility ? New GUID created, references from other components will not workProject Compatibility ? Default for a new component Binary Compatibility ? GUID does not change, references from other components will work
3. Why iss it important to use source control software for source code? Expected answer: Modification history.Code ownership: Multiple people can not modify the same code at the same time.
4. What two methods are called from the ObjectContext object to inform MTS that the transaction was successful or unsuccessful? Expected answer: SetComplete and SetAbort.
5. What is the tool used to configure the port range and protocols for DCOM communications? Expected answer: DCOMCONFIG.EXE
6. What does Option Explicit refer to? Expected answer: All variables must be declared before use. Their type is not required.
7. What are the different ways to Declare and Instantiate an object in Visual Basic 6? Expected answer: Dim obj as OBJ.CLASS with eitherSet obj = New OBJ.CLASS orSet obj = CreateObject(?OBJ.CLASS?) orSet obj = GetObject( ,? OBJ.CLASS?)orDim obj as New OBJ.CLASS
8. Name the four different cursor types in ADO and describe them briefly. Expected answer: The cursor types are listed from least to most resource intensive.Forward Only ? Fastest, can only move forward in recordset Static ? Can move to any record in the recordset. Data is static and never changes.KeySet ? Changes are detectable, records that are deleted by other users are unavailable, and records created by other users are not detectedDynamic ? All changes are visible.
9. Name the four different locking type in ADO and describe them briefly. Expected answer: LockPessimistic ? Locks the row once after any edits occur.LockOptimistic ? Locks the row only when Update is called.LockBatchOptimistic ? Allows Batch Updates.LockReadOnly ? Read only. Can not alter the data.
10. Describe Database Connection pooling (relative to MTS ) Expected answer: This allows MTS to reuse database connections. Database connections are put to ?sleep? as opposed to being created and destroyed and are activated upon request.
11. What are the ADO objects? Explain them. Provide a scenario using three of them to return data from a database. Expected answer: Connection ? Connects to a data source; contains the Errors collectionCommand ? Executes commands to the data source. Is the only object that can accept parameters for a stored procedure.Recordset ? The set of data returned from the database.Scenario: There are many possibilities. The most likely is as follows:Dim conn As ADODB.ConnectionDim rs As ADODB.RecordsetDim Cmd As ADODB.Commandconn.ConnectionString = ?CONNECTION STRING?conn.OpenSet Cmd.ActiveConnection = connCmd.CommandText = ?SQL STATEMENT?Set rs = Cmd.ExecuteSet rs.ActiveConnection = Nothingconn.Close
12. Under the ADO Command Object, what collection is responsible for input to stored procedures? Expected answer: The Parameters collection.
13. What are some benefits of using MTS? Expected answer: Database Pooling, Transactional operations, Deployment, Security, Remote Execution.
14. What is the benefit of wrapping database calls into MTS transactions? Expected answer: If database calls are made within the context of a transaction, aborting the transaction will undo and changes that occur within that transaction. This removes the possibility of stranded, or partial data.
15. Describe and In Process vs. Out of Process component. Which is faster? Expected answer:An in-process component is implemented as a DLL, and runs in the same process space as its client app, enabling the most efficient communication between client and component.Each client app that uses the component starts a new instance of it.An out of process component is implemented as an EXE, and unlike a dll, runs in its own process space. As a result, exe’s are slower then dll’s because communications between client and component must be marshalled across process boundaries. A single instance of an out of process component can service many clients.
16. What are the main components of the ADO object model? How are they used? Expected answer:Connection: Used to make a connection between your app and an external data source, ie, sql server.Command: Used to build queries, including user-specific parameters, to access records from a data source (which are returned in a Recordset)Recordset:Used to access records returned from an SQL query. With a recordset, you can navigate returned records. You can also add, modify or delete records.

ASP.NET questions, part 111

1. Explain the differences between Server-side and Client-side code? Server side scripting means that all the script will be executed by the server and interpreted as needed. ASP doesn’t have some of the functionality like sockets, uploading, etc. For these you have to make a custom components usually in VB or VC++. Client side scripting means that the script will be executed immediately in the browser such as form field validation, clock, email validation, etc. Client side scripting is usually done in VBScript or JavaScript. Download time, browser compatibility, and visible code - since JavaScript and VBScript code is included in the HTML page, then anyone can see the code by viewing the page source. Also a possible security hazards for the client computer.
2. What type of code (server or client) is found in a Code-Behind class? C#
3. Should validation (did the user enter a real date) occur server-side or client-side? Why? Client-side validation because there is no need to request a server side date when you could obtain a date from the client machine.
4. What does the "EnableViewState" property do? Why would I want it on or off? Enable ViewState turns on the automatic state management feature that enables server controls to re-populate their values on a round trip without requiring you to write any code. This feature is not free however, since the state of a control is passed to and from the server in a hidden form field. You should be aware of when ViewState is helping you and when it is not. For example, if you are binding a control to data on every round trip (as in the datagrid example in tip #4), then you do not need the control to maintain it’s view state, since you will wipe out any re-populated data in any case. ViewState is enabled for all server controls by default. To disable it, set the EnableViewState property of the control to false.
5. What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other? Server.Transfer() : client is shown as it is on the requesting page only, but the all the content is of the requested page. Data can be persist accros the pages using Context.Item collection, which is one of the best way to transfer data from one page to another keeping the page state alive. Response.Dedirect() :client know the physical loation (page name and query string as well). Context.Items loses the persisitance when nevigate to destination page. In earlier versions of IIS, if we wanted to send a user to a new Web page, the only option we had was Response.Redirect. While this method does accomplish our goal, it has several important drawbacks. The biggest problem is that this method causes each page to be treated as a separate transaction. Besides making it difficult to maintain your transactional integrity, Response.Redirect introduces some additional headaches. First, it prevents good encapsulation of code. Second, you lose access to all of the properties in the Request object. Sure, there are workarounds, but they’re difficult. Finally, Response.Redirect necessitates a round trip to the client, which, on high-volume sites, causes scalability problems. As you might suspect, Server.Transfer fixes all of these problems. It does this by performing the transfer on the server without requiring a roundtrip to the client.
6. Can you give an example of when it would be appropriate to use a web service as opposed to a non-serviced .NET component? When to Use Web Services:
   • Communicating through a Firewall When building a distributed application with 100s/1000s of users spread over multiple locations, there is always the problem of communicating between client and server because of firewalls and proxy servers. Exposing your middle tier components as Web Services and invoking the directly from a Windows UI is a very valid option.
   • Application Integration When integrating applications written in various languages and running on disparate systems. Or even applications running on the same platform that have been written by separate vendors.
   • Business-to-Business Integration This is an enabler for B2B intergtation which allows one to expose vital business processes to authorized supplier and customers. An example would be exposing electronic ordering and invoicing, allowing customers to send you purchase orders and suppliers to send you invoices electronically.
   • Software Reuse This takes place at multiple levels. Code Reuse at the Source code level or binary componet-based resuse. The limiting factor here is that you can reuse the code but not the data behind it. Webservice overcome this limitation. A scenario could be when you are building an app that aggregates the functionality of serveral other Applicatons. Each of these functions could be performed by individual apps, but there is value in perhaps combining the the multiple apps to present a unifiend view in a Portal or Intranet.
   • When not to use Web Services: Single machine Applicatons When the apps are running on the same machine and need to communicate with each other use a native API. You also have the options of using component technologies such as COM or .NET Componets as there is very little overhead.
   • Homogeneous Applications on a LAN If you have Win32 or Winforms apps that want to communicate to their server counterpart. It is much more efficient to use DCOM in the case of Win32 apps and .NET Remoting in the case of .NET Apps.
7. Let’s say I have an existing application written using Visual Studio (VBInterDevand this application utilizes WindowsCOM+ transaction services. How would you approach migrating this application to .NET?
8. Can you explain the difference between an ADO.NET Dataset and an ADO Recordset? In ADO, the in-memory representation of data is the recordset. In ADO.NET, it is the dataset. There are important differences between them.
• A recordset looks like a single table. If a recordset is to contain data from multiple database tables, it must use a JOIN query, which assembles the data from the various database tables into a single result table. In contrast, a dataset is a collection of one or more tables. The tables within a dataset are called data tables; specifically, they are DataTable objects. If a dataset contains data from multiple database tables, it will typically contain multiple DataTable objects. That is, each DataTable object typically corresponds to a single database table or view. In this way, a dataset can mimic the structure of the underlying database. A dataset usually also contains relationships. A relationship within a dataset is analogous to a foreign-key relationship in a database —that is, it associates rows of the tables with each other. For example, if a dataset contains a table about investors and another table about each investor’s stock purchases, it could also contain a relationship connecting each row of the investor table with the corresponding rows of the purchase table. Because the dataset can hold multiple, separate tables and maintain information about relationships between them, it can hold much richer data structures than a recordset, including self-relating tables and tables with many-to-many relationships.
• In ADO you scan sequentially through the rows of the recordset using the ADO MoveNext method. In ADO.NET, rows are represented as collections, so you can loop through a table as you would through any collection, or access particular rows via ordinal or primary key index. DataRelation objects maintain information about master and detail records and provide a method that allows you to get records related to the one you are working with. For example, starting from the row of the Investor table for "Nate Sun," you can navigate to the set of rows of the Purchase table describing his purchases. A cursor is a database element that controls record navigation, the ability to update data, and the visibility of changes made to the database by other users. ADO.NET does not have an inherent cursor object, but instead includes data classes that provide the functionality of a traditional cursor. For example, the functionality of a forward-only, read-only cursor is available in the ADO.NET DataReader object. For more information about cursor functionality, see Data Access Technologies.
• Minimized Open Connections: In ADO.NET you open connections only long enough to perform a database operation, such as a Select or Update. You can read rows into a dataset and then work with them without staying connected to the data source. In ADO the recordset can provide disconnected access, but ADO is designed primarily for connected access. There is one significant difference between disconnected processing in ADO and ADO.NET. In ADO you communicate with the database by making calls to an OLE DB provider. In ADO.NET you communicate with the database through a data adapter (an OleDbDataAdapter, SqlDataAdapter, OdbcDataAdapter, or OracleDataAdapter object), which makes calls to an OLE DB provider or the APIs provided by the underlying data source. The important difference is that in ADO.NET the data adapter allows you to control how the changes to the dataset are transmitted to the database — by optimizing for performance, performing data validation checks, or adding any other extra processing. Data adapters, data connections, data commands, and data readers are the components that make up a .NET Framework data provider. Microsoft and third-party providers can make available other .NET Framework data providers that can be integrated into Visual Studio.
• Sharing Data Between Applications. Transmitting an ADO.NET dataset between applications is much easier than transmitting an ADO disconnected recordset. To transmit an ADO disconnected recordset from one component to another, you use COM marshalling. To transmit data in ADO.NET, you use a dataset, which can transmit an XML stream.
• Richer data types.COM marshalling provides a limited set of data types — those defined by the COM standard. Because the transmission of datasets in ADO.NET is based on an XML format, there is no restriction on data types. Thus, the components sharing the dataset can use whatever rich set of data types they would ordinarily use.
• Performance. Transmitting a large ADO recordset or a large ADO.NET dataset can consume network resources; as the amount of data grows, the stress placed on the network also rises. Both ADO and ADO.NET let you minimize which data is transmitted. But ADO.NET offers another performance advantage, in that ADO.NET does not require data-type conversions. ADO, which requires COM marshalling to transmit records sets among components, does require that ADO data types be converted to COM data types.
• Penetrating Firewalls.A firewall can interfere with two components trying to transmit disconnected ADO recordsets. Remember, firewalls are typically configured to allow HTML text to pass, but to prevent system-level requests (such as COM marshalling) from passing.
9. Can you give an example of what might be best suited to place in the Application_Start and Session_Start subroutines? The Application_Start event is guaranteed to occur only once throughout the lifetime of the application. It’s a good place to initialize global variables. For example, you might want to retrieve a list of products from a database table and place the list in application state or the Cache object. SessionStateModule exposes both Session_Start and Session_End events.
10. If I’m developing an application that must accomodate multiple security levels though secure login and my ASP.NET web appplication is spanned across three web-servers (using round-robbin load balancing) what would be the best approach to maintain login-in state for the users?
11. What are ASP.NET Web Forms? How is this technology different than what is available though ASP? Web Forms are the heart and soul of ASP.NET. Web Forms are the User Interface (UI) elements that give your Web applications their look and feel. Web Forms are similar to Windows Forms in that they provide properties, methods, and events for the controls that are placed onto them. However, these UI elements render themselves in the appropriate markup language required by the request, e.g. HTML. If you use Microsoft Visual Studio .NET, you will also get the familiar drag-and-drop interface used to create your UI for your Web application.
12. How does VB.NET/C# achieve polymorphism? By using Abstract classes/functions.
13. Can you explain what inheritance is and an example of when you might use it? Inheritance is a fundamental feature of an object oriented system and it is simply the ability to inherit data and functionality from a parent object. Rather than developing new objects from scratch, new code can be based on the work of other programmers, adding only new features that are needed.
14. How would you implement inheritance using VB.NET/C#? When we set out to implement a class using inheritance, we must first start with an existing class from which we will derive our new subclass. This existing class, or base class, may be part of the .NET system class library framework, it may be part of some other application or .NET assembly, or we may create it as part of our existing application. Once we have a base class, we can then implement one or more subclasses based on that base class. Each of our subclasses will automatically have all of the methods, properties, and events of that base class ? including the implementation behind each method, property, and event. Our subclass can add new methods, properties, and events of its own - extending the original interface with new functionality. Additionally, a subclass can replace the methods and properties of the base class with its own new implementation - effectively overriding the original behavior and replacing it with new behaviors. Essentially inheritance is a way of merging functionality from an existing class into our new subclass. Inheritance also defines rules for how these methods, properties, and events can be merged.

C++ programming on UNIX platforms

1. What is a Make file?(Fujitsu) Make file is a utility in Unix to help compile large programs. It helps by only compiling the portion of the program that has been changed.
2. What is deadlock? (Novell) Deadlock is a situation when two or more processes prevent each other from running.Example: if T1 is holding x and waiting for y to be free and T2 holding y and waiting for x to be free deadlock happens.
3. What is semaphore? (Novell) Semaphore is a special variable, it has two methods: up and down. Semaphore performs atomic operations, which means ones a semaphore is called it can not be inturrupted.
4. Is C an object-oriented language? (Microsoft) C is not an object-oriented language, but limited object-oriented programming can be done in C.
5. Name some major differences between C++ and Java. C++ has pointers; Java does not. Java is platform-independent; C++ is not. Java has garbage collection; C++ does not.

Basic C++ and UNIX OS programming

Q1: Could you tell something about the Unix System Kernel? (from ITCO )

A1: The kernel is the heart of the UNIX openrating system, it’s reponsible for controlling the computer’s resouces and scheduling user jobs so that each one gets its fair share of resources.

Q2: What are each of the standard files and what are they normally associated with? (from ITCO )

A2: They are the standard input file, the standard output file and the standard error file. The first is usually associated with the keyboard, the second and third are usually associated with the terminal screen.

Q3: Detemine the code below, tell me exectly how many times is the operation sum++ performed ? (from ITCO )

for ( i = 0; i < j =" 100;"> 100 - i; j–)
sum++;
A3: (99 * 100)/2 = 4950
The sum++ is performed 4950 times.

Q4: Give 4 examples which belongs application layer in TCP/IP architecture? (from CISCO )

A4: FTP, TELNET, HTTP and TFTP

Q5: What’s the meaning of ARP in TCP/IP? (from CISCO )

A5: The "ARP" stands for Address Resolution Protocol. The ARP standard defines two basic message types: a request and a response. a request message contains an IP address and requests the corresponding hardware address; a replay contains both the IP address, sent in the request, and the hardware address.

C++ coding interview questions

1. Design and implement a String class that satisfies the following:

• Supports embedded nulls
• Provide the following methods (at least)
  • Constructor
  • Destructor
  • Copy constructor
  • Assignment operator
  • Addition operator (concatenation)
  • Return character at location
  • Return substring at location
  • Find substring
• Provide versions of methods for String and for char* arguments

2. Given the following classes

class Fruit {
// …
}

class Apple : public Fruit {
// …
}

class Peach : public Fruit {
// …
}

// Container of fruit
class BasketOfFruit {
BasketOfFruit() ;
void insert( Fruit & f ) ;
// …
}

// Container of apples
class BasketOfApples /* ??? */ {
// …
}

Should BasketOfApples derive from BasketOfFruit? Why or why not?
What is the general principle that determines the answer?

3. Describe briefly what the following function does. What standard function is it most like ?

int f( char *p ) {
int n = 0 ;
while ( *p != 0 ) n = 10*n + *p++ - ‘0′ ;
return n ;
}

4. Describe briefly what function ‘a’ does in the following code fragment.

struct s {
struct s *next ;
}

a( struct s *p, struct s *x ) {
while ( p->next != 0 ) p = p->next ;
p->next = x ;
x->next = 0 ;
}

5. What default methods are declared implicitly by the C++ compiler for the class below:

class Empty
{
};

6. Given a system with a hard realtime priority, multithreaded architecture, with priorities from 1 (least) to 5 (most), explain the major flaw in the design below:

The following objects are shared between the threads:

Disk : This class is a singleton. The read() and write() methods both block on a simple atomic lock()/unlock() shared between the two. (ie, only one thread can access the disk, thru either read or write, at any given time). It also has a waitForData() method, which blocks (without claiming the lock) until either a timeout elapses, or data is ready. It returns true upon returning due to new data, false upon returning due to the timeout.

Network : This class is a singleton. The read() and write() methods both block on a simple atomic lock()/unlock() shared between the two. (ie, only one thread can access the disk, thru either read or write, at any given time).

Sensor: The Sensor class accesses a number of physical sensors. The first method, ‘waitForData()’, blocks until data has been collected from the sensors. The second method, ‘processData()’, does a series of long and cpu-intensive calculations on the data. These calculations often take several minutes. It then returns the processed data.

Each of the following threads is running concurrently. Assume that the psuedocode in each thread is looped infinitely (ie, encased in a while(true) { }. It is extremely important that information buffered to the disk be sent to the network as quickly as possible, this is why Thread 1 runs at priority 5. The system conditions checked in thread 3 are not particularly important events (not as important as the calculations done in thread 2). If the events aren’t transmitted over the network for several minutes, it’s not a problem at all. They do, however, contain a large amount of system information. Thread 4 watches for serious system alarms, indicating serious problems. These are a serious concern and if not quickly buffered to the disk and sent to the network, can cause serious revenue loss.

Thread 1: (priority: 5)
while(!Disk.waitForData()) { yield(); } /* Wait until someone has
written data to the disk */
Network.write(Disk.read()); /* Write the data buffered on the disk to
the network */

Thread 2: (priority: 2)
while(!Sensor.waitForData()) { yield(); } /* Wait until the sensors
have picked up data */
Disk.write(Sensor.processData()); /* process the data and write it to
the disk. */

Thread 3: (priority: 1)

if (checkSystemCondition1()) /* If system condition 1 is true.. */
Disk.write(SystemCond1Data); /* Grab the data on the system
condition and buffer it to disk */
if (checkSystemCondition2()) /* see above*/
Disk.write(SystemCond2Data);
if (checkSystemCondition3()) /* see above */
Disk.write(SystemCond3Data);
yield();

Thread 4: (priority: 4)
if (checkAlarms()) /* If any serious alarms exist */
Disk.write(AlarmData); /* Buffer that data to disk for immediate
network transmit */
yield();

Advanced C++ and STL interview questions

Q: How do you link a C++ program to C functions?

A: By using the extern "C" linkage specification around the C function declarations.

Q: Explain the scope resolution operator.

A: It permits a program to reference an identifier in the global scope that has been hidden by another identifier with the same name in the local scope.

Q: What are the differences between a C++ struct and C++ class?

A: The default member and base-class access specifiers are different.

Q: How many ways are there to initialize an int with a constant?

A: Two.

There are two formats for initializers in C++ as shown in the example that follows. The first format uses the traditional C notation. The second format uses constructor notation.

int foo = 123;

int bar (123);

Q: How does throwing and catching exceptions differ from using setjmp and longjmp?

A: The throw operation calls the destructors for automatic objects instantiated since entry to the try block.

Q: What is your reaction to this line of code?

delete this;

A: It’s not a good practice.

Q: What is a default constructor?

A: A constructor that has no arguments.

Q: What is a conversion constructor?

A: A constructor that accepts one argument of a different type.

Q: What is the difference between a copy constructor and an overloaded assignment operator?

A: A copy constructor constructs a new object by using the content of the argument object. An overloaded assignment operator assigns the contents of an existing object to another existing object of the same class.

Q: When should you use multiple inheritance?

A: There are three acceptable answers: "Never," "Rarely," and "When the problem domain cannot be accurately modeled any other way."

Q: What is a virtual destructor?

A: The simple answer is that a virtual destructor is one that is declared with the virtual attribute.

Q: Explain the ISA and HASA class relationships. How would you implement each in a class design?

A: A specialized class "is" a specialization of another class and, therefore, has the ISA relationship with the other class. An Employee ISA Person. This relationship is best implemented with inheritance. Employee is derived from Person. A class may have an instance of another class. For example, an employee "has" a salary, therefore the Employee class has the HASA relationship with the Salary class. This relationship is best implemented by embedding an object of the Salary class in the Employee class.

Q: When is a template a better solution than a base class?

A: When you are designing a generic class to contain or otherwise manage objects of other types, when the format and behavior of those other types are unimportant to their containment or management, and particularly when those other types are unknown (thus, the genericity) to the designer of the container or manager class.

Q: What is a mutable member?

A: One that can be modified by the class even when the object of the class or the member function doing the modification is const.

Q: What is an explicit constructor?

A: A conversion constructor declared with the explicit keyword. The compiler does not use an explicit constructor to implement an implied conversion of types. It’s purpose is reserved explicitly for construction.

Q: What is the Standard Template Library?

A: A library of container templates approved by the ANSI committee for inclusion in the standard C++ specification.

A programmer who then launches into a discussion of the generic programming model, iterators, allocators, algorithms, and such, has a higher than average understanding of the new technology that STL brings to C++ programming.

Q: Describe run-time type identification.

A: The ability to determine at run time the type of an object by using the typeid operator or the dynamic_cast operator.

Q: What problem does the namespace feature solve?

A: Multiple providers of libraries might use common global identifiers causing a name collision when an application tries to link with two or more such libraries. The namespace feature surrounds a library’s external declarations with a unique namespace that eliminates the potential for those collisions.

This solution assumes that two library vendors don’t use the same namespace identifier, of course.

Q: Are there any new intrinsic (built-in) data types?

A: Yes. The ANSI committee added the bool intrinsic type and its true and false value keywords.

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Windows Server 2003 Active Directory and Security questions

1. What’s the difference between local, global and universal groups? Domain local groups assign access permissions to global domain groups for local domain resources. Global groups provide access to resources in other trusted domains. Universal groups grant access to resources in all trusted domains.
2. I am trying to create a new universal user group. Why can’t I? Universal groups are allowed only in native-mode Windows Server 2003 environments. Native mode requires that all domain controllers be promoted to Windows Server 2003 Active Directory.
3. What is LSDOU? It’s group policy inheritance model, where the policies are applied to Local machines, Sites, Domains and Organizational Units.
4. Why doesn’t LSDOU work under Windows NT? If the NTConfig.pol file exist, it has the highest priority among the numerous policies.
5. Where are group policies stored? %SystemRoot%System32\GroupPolicy
6. What is GPT and GPC? Group policy template and group policy container.
7. Where is GPT stored? %SystemRoot%\SYSVOL\sysvol\domainname\Policies\GUID
8. You change the group policies, and now the computer and user settings are in conflict. Which one has the highest priority? The computer settings take priority.
9. You want to set up remote installation procedure, but do not want the user to gain access over it. What do you do? gponame–> User Configuration–> Windows Settings–> Remote Installation Services–> Choice Options is your friend.
10. What’s contained in administrative template conf.adm? Microsoft NetMeeting policies
11. How can you restrict running certain applications on a machine? Via group policy, security settings for the group, then Software Restriction Policies.
12. You need to automatically install an app, but MSI file is not available. What do you do? A .zap text file can be used to add applications using the Software Installer, rather than the Windows Installer.
13. What’s the difference between Software Installer and Windows Installer? The former has fewer privileges and will probably require user intervention. Plus, it uses .zap files.
14. What can be restricted on Windows Server 2003 that wasn’t there in previous products? Group Policy in Windows Server 2003 determines a users right to modify network and dial-up TCP/IP properties. Users may be selectively restricted from modifying their IP address and other network configuration parameters.
15. How frequently is the client policy refreshed? 90 minutes give or take.
16. Where is secedit? It’s now gpupdate.
17. You want to create a new group policy but do not wish to inherit. Make sure you check Block inheritance among the options when creating the policy.
18. What is "tattooing" the Registry? The user can view and modify user preferences that are not stored in maintained portions of the Registry. If the group policy is removed or changed, the user preference will persist in the Registry.
19. How do you fight tattooing in NT/2000 installations? You can’t.
20. How do you fight tattooing in 2003 installations? User Configuration - Administrative Templates - System - Group Policy - enable - Enforce Show Policies Only.
21. What does IntelliMirror do? It helps to reconcile desktop settings, applications, and stored files for users, particularly those who move between workstations or those who must periodically work offline.
22. What’s the major difference between FAT and NTFS on a local machine? FAT and FAT32 provide no security over locally logged-on users. Only native NTFS provides extensive permission control on both remote and local files.
23. How do FAT and NTFS differ in approach to user shares? They don’t, both have support for sharing.
24. Explan the List Folder Contents permission on the folder in NTFS. Same as Read & Execute, but not inherited by files within a folder. However, newly created subfolders will inherit this permission.
25. I have a file to which the user has access, but he has no folder permission to read it. Can he access it? It is possible for a user to navigate to a file for which he does not have folder permission. This involves simply knowing the path of the file object. Even if the user can’t drill down the file/folder tree using My Computer, he can still gain access to the file using the Universal Naming Convention (UNC). The best way to start would be to type the full path of a file into Run… window.
26. For a user in several groups, are Allow permissions restrictive or permissive? Permissive, if at least one group has Allow permission for the file/folder, user will have the same permission.
27. For a user in several groups, are Deny permissions restrictive or permissive? Restrictive, if at least one group has Deny permission for the file/folder, user will be denied access, regardless of other group permissions.
28. What hidden shares exist on Windows Server 2003 installation? Admin$, Drive$, IPC$, NETLOGON, print$ and SYSVOL.
29. What’s the difference between standalone and fault-tolerant DFS (Distributed File System) installations? The standalone server stores the Dfs directory tree structure or topology locally. Thus, if a shared folder is inaccessible or if the Dfs root server is down, users are left with no link to the shared resources. A fault-tolerant root node stores the Dfs topology in the Active Directory, which is replicated to other domain controllers. Thus, redundant root nodes may include multiple connections to the same data residing in different shared folders.
30. We’re using the DFS fault-tolerant installation, but cannot access it from a Win98 box. Use the UNC path, not client, only 2000 and 2003 clients can access Server 2003 fault-tolerant shares.
31. Where exactly do fault-tolerant DFS shares store information in Active Directory? In Partition Knowledge Table, which is then replicated to other domain controllers.
32. Can you use Start->Search with DFS shares? Yes.
33. What problems can you have with DFS installed? Two users opening the redundant copies of the file at the same time, with no file-locking involved in DFS, changing the contents and then saving. Only one file will be propagated through DFS.
34. I run Microsoft Cluster Server and cannot install fault-tolerant DFS. Yeah, you can’t. Install a standalone one.
35. Is Kerberos encryption symmetric or asymmetric? Symmetric.
36. How does Windows 2003 Server try to prevent a middle-man attack on encrypted line? Time stamp is attached to the initial client request, encrypted with the shared key.
37. What hashing algorithms are used in Windows 2003 Server? RSA Data Security’s Message Digest 5 (MD5), produces a 128-bit hash, and the Secure Hash Algorithm 1 (SHA-1), produces a 160-bit hash.
38. What third-party certificate exchange protocols are used by Windows 2003 Server? Windows Server 2003 uses the industry standard PKCS-10 certificate request and PKCS-7 certificate response to exchange CA certificates with third-party certificate authorities.
39. What’s the number of permitted unsuccessful logons on Administrator account? Unlimited. Remember, though, that it’s the Administrator account, not any account that’s part of the Administrators group.
40. If hashing is one-way function and Windows Server uses hashing for storing passwords, how is it possible to attack the password lists, specifically the ones using NTLMv1? A cracker would launch a dictionary attack by hashing every imaginable term used for password and then compare the hashes.
41. What’s the difference between guest accounts in Server 2003 and other editions? More restrictive in Windows Server 2003.
42. How many passwords by default are remembered when you check "Enforce Password History Remembered"? User’s last 6 passwords.

Windows Server 2003 interview and certification questions

1. How do you double-boot a Win 2003 server box? The Boot.ini file is set as read-only, system, and hidden to prevent unwanted editing. To change the Boot.ini timeout and default settings, use the System option in Control Panel from the Advanced tab and select Startup.
2. What do you do if earlier application doesn’t run on Windows Server 2003? When an application that ran on an earlier legacy version of Windows cannot be loaded during the setup function or if it later malfunctions, you must run the compatibility mode function. This is accomplished by right-clicking the application or setup program and selecting Properties –> Compatibility –> selecting the previously supported operating system.
3. If you uninstall Windows Server 2003, which operating systems can you revert to? Win ME, Win 98, 2000, XP. Note, however, that you cannot upgrade from ME and 98 to Windows Server 2003.
4. How do you get to Internet Firewall settings? Start –> Control Panel –> Network and Internet Connections –> Network Connections.
5. What are the Windows Server 2003 keyboard shortcuts? Winkey opens or closes the Start menu. Winkey + BREAK displays the System Properties dialog box. Winkey + TAB moves the focus to the next application in the taskbar. Winkey + SHIFT + TAB moves the focus to the previous application in the taskbar. Winkey + B moves the focus to the notification area. Winkey + D shows the desktop. Winkey + E opens Windows Explorer showing My Computer. Winkey + F opens the Search panel. Winkey + CTRL + F opens the Search panel with Search for Computers module selected. Winkey + F1 opens Help. Winkey + M minimizes all. Winkey + SHIFT+ M undoes minimization. Winkey + R opens Run dialog. Winkey + U opens the Utility Manager. Winkey + L locks the computer.
6. What is Active Directory? Active Directory is a network-based object store and service that locates and manages resources, and makes these resources available to authorized users and groups. An underlying principle of the Active Directory is that everything is considered an object—people, servers, workstations, printers, documents, and devices. Each object has certain attributes and its own security access control list (ACL).
7. Where are the Windows NT Primary Domain Controller (PDC) and its Backup Domain Controller (BDC) in Server 2003? The Active Directory replaces them. Now all domain controllers share a multimaster peer-to-peer read and write relationship that hosts copies of the Active Directory.
8. How long does it take for security changes to be replicated among the domain controllers? Security-related modifications are replicated within a site immediately. These changes include account and individual user lockout policies, changes to password policies, changes to computer account passwords, and modifications to the Local Security Authority (LSA).
9. What’s new in Windows Server 2003 regarding the DNS management? When DC promotion occurs with an existing forest, the Active Directory Installation Wizard contacts an existing DC to update the directory and replicate from the DC the required portions of the directory. If the wizard fails to locate a DC, it performs debugging and reports what caused the failure and how to fix the problem. In order to be located on a network, every DC must register in DNS DC locator DNS records. The Active Directory Installation Wizard verifies a proper configuration of the DNS infrastructure. All DNS configuration debugging and reporting activity is done with the Active Directory Installation Wizard.
10. When should you create a forest? Organizations that operate on radically different bases may require separate trees with distinct namespaces. Unique trade or brand names often give rise to separate DNS identities. Organizations merge or are acquired and naming continuity is desired. Organizations form partnerships and joint ventures. While access to common resources is desired, a separately defined tree can enforce more direct administrative and security restrictions.
11. How can you authenticate between forests? Four types of authentication are used across forests: (1) Kerberos and NTLM network logon for remote access to a server in another forest; (2) Kerberos and NTLM interactive logon for physical logon outside the user’s home forest; (3) Kerberos delegation to N-tier application in another forest; and (4) user principal name (UPN) credentials.
12. What snap-in administrative tools are available for Active Directory? Active Directory Domains and Trusts Manager, Active Directory Sites and Services Manager, Active Directory Users and Group Manager, Active Directory Replication (optional, available from the Resource Kit), Active Directory Schema Manager (optional, available from adminpak)
13. What types of classes exist in Windows Server 2003 Active Directory?
    • Structural class. The structural class is important to the system administrator in that it is the only type from which new Active Directory objects are created. Structural classes are developed from either the modification of an existing structural type or the use of one or more abstract classes.
    • Abstract class. Abstract classes are so named because they take the form of templates that actually create other templates (abstracts) and structural and auxiliary classes. Think of abstract classes as frameworks for the defining objects.
    • Auxiliary class. The auxiliary class is a list of attributes. Rather than apply numerous attributes when creating a structural class, it provides a streamlined alternative by applying a combination of attributes with a single include action.
    • 88 class. The 88 class includes object classes defined prior to 1993, when the 1988 X.500 specification was adopted. This type does not use the structural, abstract, and auxiliary definitions, nor is it in common use for the development of objects in Windows Server 2003 environments.
14. How do you delete a lingering object? Windows Server 2003 provides a command called Repadmin that provides the ability to delete lingering objects in the Active Directory.
15. What is Global Catalog? The Global Catalog authenticates network user logons and fields inquiries about objects across a forest or tree. Every domain has at least one GC that is hosted on a domain controller. In Windows 2000, there was typically one GC on every site in order to prevent user logon failures across the network.
16. How is user account security established in Windows Server 2003? When an account is created, it is given a unique access number known as a security identifier (SID). Every group to which the user belongs has an associated SID. The user and related group SIDs together form the user account’s security token, which determines access levels to objects throughout the system and network. SIDs from the security token are mapped to the access control list (ACL) of any object the user attempts to access.
17. If I delete a user and then create a new account with the same username and password, would the SID and permissions stay the same? No. If you delete a user account and attempt to recreate it with the same user name and password, the SID will be different.
18. What do you do with secure sign-ons in an organization with many roaming users? Credential Management feature of Windows Server 2003 provides a consistent single sign-on experience for users. This can be useful for roaming users who move between computer systems. The Credential Management feature provides a secure store of user credentials that includes passwords and X.509 certificates.
19. Anything special you should do when adding a user that has a Mac? "Save password as encrypted clear text" must be selected on User Properties Account Tab Options, since the Macs only store their passwords that way.
20. What remote access options does Windows Server 2003 support? Dial-in, VPN, dial-in with callback.
21. Where are the documents and settings for the roaming profile stored? All the documents and environmental settings for the roaming user are stored locally on the system, and, when the user logs off, all changes to the locally stored profile are copied to the shared server folder. Therefore, the first time a roaming user logs on to a new system the logon process may take some time, depending on how large his profile folder is.
22. Where are the settings for all the users stored on a given machine? \Document and Settings\All Users
23. What languages can you use for log-on scripts? JavaScipt, VBScript, DOS batch files (.com, .bat, or even .exe)

Hardware design interview questions

1. Give two ways of converting a two input NAND gate to an inverter
2. Given a circuit, draw its exact timing response. (I was given a Pseudo Random Signal Generator; you can expect any sequential ckt)
3. What are set up time & hold time constraints? What do they signify? Which one is critical for estimating maximum clock frequency of a circuit?
4. Give a circuit to divide frequency of clock cycle by two
5. Design a divide-by-3 sequential circuit with 50% duty circle. (Hint: Double the Clock)
6. Suppose you have a combinational circuit between two registers driven by a clock. What will you do if the delay of the combinational circuit is greater than your clock signal? (You can’t resize the combinational circuit transistors)
7. The answer to the above question is breaking the combinational circuit and pipelining it. What will be affected if you do this?
8. What are the different Adder circuits you studied?
9. Give the truth table for a Half Adder. Give a gate level implementation of the same.
10. Draw a Transmission Gate-based D-Latch.
11. Design a Transmission Gate based XOR. Now, how do you convert it to XNOR? (Without inverting the output)
12. How do you detect if two 8-bit signals are same?
13. How do you detect a sequence of "1101" arriving serially from a signal line?
14. Design any FSM in VHDL or Verilog.
15. Explain RC circuit’s charging and discharging.
16. Explain the working of a binary counter.
17. Describe how you would reverse a singly linked list.

Windows Server 2003 IIS and Scripting interview questions

1. What is presentation layer responsible for in the OSI model? The presentation layer establishes the data format prior to passing it along to the network application’s interface. TCP/IP networks perform this task at the application layer.
2. Does Windows Server 2003 support IPv6? Yes, run ipv6.exe from command line to disable it.
3. Can Windows Server 2003 function as a bridge? Yes, and it’s a new feature for the 2003 product. You can combine several networks and devices connected via several adapters by enabling IP routing.
4. What’s the difference between the basic disk and dynamic disk? The basic type contains partitions, extended partitions, logical drivers, and an assortment of static volumes; the dynamic type does not use partitions but dynamically manages volumes and provides advanced storage options
5. What’s a media pool? It is any compilation of disks or tapes with the same administrative properties.
6. How do you install recovery console? C:\i386\win32 /cmdcons, assuming that your Win server installation is on drive C.
7. What’s new in Terminal Services for Windows 2003 Server? Supports audio transmissions as well, although prepare for heavy network load.
8. What scripts ship with IIS 6.0? iisweb.vsb to create, delete, start, stop, and list Web sites, iisftp.vsb to create, delete, start, stop, and list FTP sites, iisdir.vsb to create, delete, start, stop, and display virtual directories, iisftpdr.vsb to create, delete, start, stop, and display virtual directories under an FTP root, iiscnfg.vbs to export and import IIS configuration to an XML file.
9. What’s the name of the user who connects to the Web site anonymously? IUSR_computername
10. What secure authentication and encryption mechanisms are supported by IIS 6.0? Basic authentication, Digest authentication, Advanced digest authentication, Certificate-based Web transactions that use PKCS #7/PKCS #10, Fortezza, SSL, Server-Gated Cryptography, Transport Layer Security
11. What’s the relation between SSL and TLS? Transport Layer Security (TLS) extends SSL by providing cryptographic authentication.
12. What’s the role of http.sys in IIS? It is the point of contact for all incoming HTTP requests. It listens for requests and queues them until they are all processed, no more queues are available, or the Web server is shut down.
13. Where’s ASP cache located on IIS 6.0? On disk, as opposed to memory, as it used to be in IIS 5.
14. What is socket pooling? Non-blocking socket usage, introduced in IIS 6.0. More than one application can use a given socket.
15. Describe the process of clustering with Windows 2003 Server when a new node is added. As a node goes online, it searches for other nodes to join by polling the designated internal network. In this way, all nodes are notified of the new node’s existence. If other nodes cannot be found on a preexisting cluster, the new node takes control of the quorum resources residing on the shared disk that contains state and configuration data.
16. What applications are not capable of performing in Windows 2003 Server clusters? The ones written exclusively for NetBEUI and IPX.
17. What’s a heartbeat? Communication processes between the nodes designed to ensure node’s health.
18. What’s a threshold in clustered environment? The number of times a restart is attempted, when the node fails.
19. You need to change and admin password on a clustered Windows box, but that requires rebooting the cluster, doesn’t it? No, it doesn’t. In 2003 environment you can do that via cluster.exe utility which does not require rebooting the entire cluster.
20. For the document of size 1 MB, what size would you expect the index to be with Indexing Service? 150-300 KB, 15-30% is a reasonable expectation.
21. Doesn’t the Indexing Service introduce a security flaw when allowing access to the index? No, because users can only view the indices of documents and folders that they have permissions for.
22. What’s the typical size of the index? Less then 100K documents - up to 128 MB. More than that - 256+ MB.
23. Which characters should be enclosed in quotes when searching the index? &, @, $, #, ^, ( ), and |.
24. How would you search for C++? Just enter C++, since + is not a special character (and neither is C).
25. What about Barnes&Noble? Should be searched for as Barnes’&’Noble.
26. Are the searches case-sensitive? No.
27. What’s the order of precedence of Boolean operators in Microsoft Windows 2003 Server Indexing Service? NOT, AND, NEAR, OR.
28. What’s a vector space query? A multiple-word query where the weight can be assigned to each of the search words. For example, if you want to fight information on ‘black hole’, but would prefer to give more weight to the word hole, you can enter black[1] hole[20] into the search window.
29. What’s a response queue? It’s the message queue that holds response messages sent from the receiving application to the sender.
30. What’s MQPing used for? Testing Microsoft Message Queue services between the nodes on a network.
31. Which add-on package for Windows 2003 Server would you use to monitor the installed software and license compliance? SMS (System Management Server).
32. Which service do you use to set up various alerts? MOM (Microsoft Operations Manager).
33. What languages does Windows Scripting Host support? VB, VBScript, JScript.

C++ algorithm specific interview questions

Q1 What are the advantages and disadvantages of B-star trees over Binary trees? (Asked by Motorola people)

A1 B-star trees have better data structure and are faster in search than Binary trees, but it’s harder to write codes for B-start trees.

Q2 Write the psuedo code for the Depth first Search.(Asked by Microsoft)

A2

dfs(G, v) //OUTLINE
Mark v as "discovered"
For each vertex w such that edge vw is in G:
If w is undiscovered:
dfs(G, w); that is, explore vw, visit w, explore from there
as much as possible, and backtrack from w to v.
Otherwise:
"Check" vw without visiting w.
Mark v as "finished".

Q3 Describe one simple rehashing policy.(Asked by Motorola people)

A3 The simplest rehashing policy is linear probing. Suppose a key K hashes to location i. Suppose other key occupies H[i]. The following function is used to generate alternative locations:

rehash(j) = (j + 1) mod h

where j is the location most recently probed. Initially j = i, the hash code for K. Notice that this version of rehash does not depend on K.

Q4 Describe Stacks and name a couple of places where stacks are useful. (Asked by Microsoft)

A4 A Stack is a linear structure in which insertions and deletions are always made at one end, called the top. This updating policy is called last in, first out (LIFO). It is useful when we need to check some syntex errors, such as missing parentheses.

Q5 Suppose a 3-bit sequence number is used in the selective-reject ARQ, what is the maximum number of frames that could be transmitted at a time? (Asked by Cisco)

A5 If a 3-bit sequence number is used, then it could distinguish 8 different frames. Since the number of frames that could be transmitted at a time is no greater half the numner of frames that could be distinguished by the sequence number, so at most 4 frames can be transmitted at a time.

Basic C++ interview questions

1.Question: Suppose that data is an array of 1000 integers. Write a single function call that will sort the 100 elements data [222] through data [321].
Answer: quicksort ((data + 222), 100);

2.Question: Which recursive sorting technique always makes recursive calls to sort subarrays that are about half size of the original array?
Answer: Mergesort always makes recursive calls to sort subarrays that are about half size of the original array, resulting in O(n log n) time.

3.Question: What is the difference between an external iterator and an internal iterator? Describe an advantage of an external iterator.
Answer: .An internal iterator is implemented with member functions of the class that has items to step through. .An external iterator is implemented as a separate class that can be "attach" to the object that has items to step through. .An external iterator has the advantage that many difference iterators can be active simultaneously on the same object.

4.Question: Why are arrays usually processed with for loop?
Answer: The real power of arrays comes from their facility of using an index variable to traverse the array, accessing each element with the same expression a[i]. All the is needed to make this work is a iterated statement in which the variable i serves as a counter, incrementing from 0 to a.length -1. That is exactly what a loop does.

5.Question: What is an HTML tag?
Answer: An HTML tag is a syntactical construct in the HTML language that abbreviates specific instructions to be executed when the HTML script is loaded into a Web browser. It is like a method in Java, a function in C++, a procedure in Pascal, or a subroutine in FORTRAN.

C++ networking questions 12345

Q: What is the difference between Stack and Queue?

A: Stack is a Last In First Out (LIFO) data structure.

Queue is a First In First Out (FIFO) data structure

Q: Write a fucntion that will reverse a string. (Microsoft)

A: char *strrev(char *s)

{

int i = 0, len = strlen(s);

char *str;

if ((str = (char *)malloc(len+1)) == NULL) /*cannot allocate memory */

err_num = 2;

return (str);

}

while(len)

str[i++]=s[--len];

str[i] = NULL;

return (str);

}

Q: What is the software Life-Cycle?

A: The software Life-Cycle are

1) Analysis and specification of the task

2) Design of the algorithms and data structures

3) Implementation (coding)

4) Testing

5) Maintenance and evolution of the system

6) Obsolescence

Q: What is the difference between a Java application and a Java applet?

A: The difference between a Java application and a Java applet is that a

Java application is a program that can be executed using the Java

interpeter, and a JAVA applet can be transfered to different networks

and executed by using a web browser (transferable to the WWW).

Q: Name 7 layers of the OSI Reference Model? (from Cisco)

A: -Application layer

-Presentation layer

-Session layer

-Transport layer

-Network layer

-Data Link layer

-Physical layer

Basic Java interview questions

1. Why do you prefer Java?

Answer: write once ,run anywhere.

2. Name some of the classes which provide the functionality of collation?

Answer: collator, rulebased collator, collationkey, collationelement iterator.

3. Awt stands for? and what is it?

Answer: AWT stands for Abstract window tool kit. It is a is a package that provides an integrated set of classes to manage user interface components.

4. why a java program can not directly communicate with an ODBC driver?

Answer: Since ODBC API is written in C language and makes use of pointers which Java can not support.

5. Are servlets platform independent? If so Why? Also what is the most common application of servlets?

Answer: Yes, Because they are written in Java. The most common application of servlet is to access database and dynamically construct HTTP response

Database management interview questions

1. What is a Cartesian product? What causes it?

Expected answer:
A Cartesian product is the result of an unrestricted join of two or more tables. The result set of a three table Cartesian product will have x * y * z number of rows where x, y, z correspond to the number of rows in each table involved in the join. It is causes by specifying a table in the FROM clause without joining it to another table.

2. What is an advantage to using a stored procedure as opposed to passing an SQL query from an application.

Expected answer:
A stored procedure is pre-loaded in memory for faster execution. It allows the DBMS control of permissions for security purposes. It also eliminates the need to recompile components when minor changes occur to the database.

3. What is the difference of a LEFT JOIN and an INNER JOIN statement?

Expected answer:
A LEFT JOIN will take ALL values from the first declared table and matching values from the second declared table based on the column the join has been declared on. An INNER JOIN will take only matching values from both tables

4. When a query is sent to the database and an index is not being used, what type of execution is taking place?

Expected answer:
A table scan.

5. What are the pros and cons of using triggers?

Expected answer:
A trigger is one or more statements of SQL that are being executed in event of data modification in a table to which the trigger belongs.

Triggers enhance the security, efficiency, and standardization of databases.
Triggers can be beneficial when used:
– to check or modify values before they are actually updated or inserted in the database. This is useful if you need to transform data from the way the user sees it to some internal database format.
– to run other non-database operations coded in user-defined functions
– to update data in other tables. This is useful for maintaining relationships between data or in keeping audit trail information.
– to check against other data in the table or in other tables. This is useful to ensure data integrity when referential integrity constraints aren’t appropriate, or when table check constraints limit checking to the current table only.

6. What are the pros and cons of using stored procedures. When would you use them?

7. What are the pros and cons of using cursors? When would you use them?

C++ object-oriented interview questions

1. How do you write a function that can reverse a linked-list? (Cisco System)

void reverselist(void)
{
 if(head==0)
  return;
 if(head->next==0)
  return;
 if(head->next==tail)
 {
  head->next = 0;
  tail->next = head;
 }
 else
 {
  node* pre = head;
  node* cur = head->next;
  node* curnext = cur->next;
  head->next = 0;
  cur->next = head;

  for(; curnext!=0; )
  {
   cur->next = pre;
   pre = cur;
   cur = curnext;
   curnext = curnext->next;
  }

  curnext->next = cur;
 }
}

2. What is polymorphism?

Polymorphism is the idea that a base class can be inherited by several classes. A base class pointer can point to its child class and a base class array can store different child class objects.

3. How do you find out if a linked-list has an end? (i.e. the list is not a cycle)

You can find out by using 2 pointers. One of them goes 2 nodes each time. The second one goes at 1 nodes each time. If there is a cycle, the one that goes 2 nodes each time will eventually meet the one that goes slower. If that is the case, then you will know the linked-list is a cycle.

4. How can you tell what shell you are running on UNIX system?

You can do the Echo $RANDOM. It will return a undefined variable if you are from the C-Shell, just a return prompt if you are from the Bourne shell, and a 5 digit random numbers if you are from the Korn shell. You could also do a ps -l and look for the shell with the highest PID.

5. What is Boyce Codd Normal form?

A relation schema R is in BCNF with respect to a set F of functional dependencies if for all functional dependencies in F+ of the form a->b, where a and b is a subset of R, at least one of the following holds:

a->b is a trivial functional dependency (b is a

VLSI and hardware engineering interview questions

1. Explain why & how a MOSFET works
2. Draw Vds-Ids curve for a MOSFET. Now, show how this curve changes (a) with increasing Vgs (b) with increasing transistor width (c) considering Channel Length Modulation
3. Explain the various MOSFET Capacitances & their significance
4. Draw a CMOS Inverter. Explain its transfer characteristics
5. Explain sizing of the inverter
6. How do you size NMOS and PMOS transistors to increase the threshold voltage?
7. What is Noise Margin? Explain the procedure to determine Noise Margin
8. Give the expression for CMOS switching power dissipation
9. What is Body Effect?
10. Describe the various effects of scaling
11. Give the expression for calculating Delay in CMOS circuit
12. What happens to delay if you increase load capacitance?
13. What happens to delay if we include a resistance at the output of a CMOS circuit?
14. What are the limitations in increasing the power supply to reduce delay?
15. How does Resistance of the metal lines vary with increasing thickness and increasing length?
16. You have three adjacent parallel metal lines. Two out of phase signals pass through the outer two metal lines. Draw the waveforms in the center metal line due to interference. Now, draw the signals if the signals in outer metal lines are in phase with each other
17. What happens if we increase the number of contacts or via from one metal layer to the next?
18. Draw a transistor level two input NAND gate. Explain its sizing (a) considering Vth (b) for equal rise and fall times
19. Let A & B be two inputs of the NAND gate. Say signal A arrives at the NAND gate later than signal B. To optimize delay, of the two series NMOS inputs A & B, which one would you place near the output?
20. Draw the stick diagram of a NOR gate. Optimize it
21. For CMOS logic, give the various techniques you know to minimize power consumption
22. What is Charge Sharing? Explain the Charge Sharing problem while sampling data from a Bus
23. Why do we gradually increase the size of inverters in buffer design? Why not give the output of a circuit to one large inverter?
24. In the design of a large inverter, why do we prefer to connect small transistors in parallel (thus increasing effective width) rather than lay out one transistor with large width?
25. Given a layout, draw its transistor level circuit. (I was given a 3 input AND gate and a 2 input Multiplexer. You can expect any simple 2 or 3 input gates)
26. Give the logic expression for an AOI gate. Draw its transistor level equivalent. Draw its stick diagram
27. Why don’t we use just one NMOS or PMOS transistor as a transmission gate?
28. For a NMOS transistor acting as a pass transistor, say the gate is connected to VDD, give the output for a square pulse input going from 0 to VDD
29. Draw a 6-T SRAM Cell and explain the Read and Write operations
30. Draw the Differential Sense Amplifier and explain its working. Any idea how to size this circuit? (Consider Channel Length Modulation)
31. What happens if we use an Inverter instead of the Differential Sense Amplifier?
32. Draw the SRAM Write Circuitry
33. Approximately, what were the sizes of your transistors in the SRAM cell? How did you arrive at those sizes?
34. How does the size of PMOS Pull Up transistors (for bit & bit- lines) affect SRAM’s performance?
35. What’s the critical path in a SRAM?
36. Draw the timing diagram for a SRAM Read. What happens if we delay the enabling of Clock signal?
37. Give a big picture of the entire SRAM Layout showing your placements of SRAM Cells, Row Decoders, Column Decoders, Read Circuit, Write Circuit and Buffers
38. In a SRAM layout, which metal layers would you prefer for Word Lines and Bit Lines? Why?
39. How can you model a SRAM at RTL Level?
40. What’s the difference between Testing & Verification?
41. For an AND-OR implementation of a two input Mux, how do you test for Stuck-At-0 and Stuck-At-1 faults at the internal nodes? (You can expect a circuit with some redundant logic)
42. What is Latch Up? Explain Latch Up with cross section of a CMOS Inverter. How do you avoid Latch Up?

C++ algorithms interview questions from Microsoft and IBM

(From Microsoft) Assume I have a linked list contains all of the alphabets from ‘A’ to ‘Z’. I want to find the letter ‘Q’ in the list, how does you perform the search to find the ‘Q’?Answer: In a linked list, we only know about the header and other elements are invisible unless we go through the node one by one. Since we have go through every single node to find ‘Q’, the search time for a linked list is linear which is O (N).

From IBM) How do you think about your school?
: I enjoy studying in our school because we have many professors and instructors are from local companies. Their professions lead us more close to local industries.

(From IBM) What classes you have enjoyed the most during your school years?
Answer: I like the class I am taking this semester, which involves a group project that needs great amount of team efforts. I really enjoy work with a group of people because we can learn new materials mutually.

>

m IBM) According to your group project you just mentioned, what’s the responsibility for each member in your group?
Answer: We have five people in our group. So far we have two web servers set up; one will be the back up system and the other will be the main system. Our leader coordinates the schedule. Two members are working on the database and do the coding for the connection between database and Java serverlets. One member is working on the user browser interface. All members will assign some classes to work on and perform the final test at the end. We have group meeting every Saturday to ensure our schedule is on track.

Can you work under pressure?
Answer: I worked for Sega of America in the hardware development group three years ago. They were working on the next generation of gaming machine (which is the “Dreamcast” we seen today in the market). My duty was to ensure the quality of prototypes that just built from manufacture were ready for engineers to test. I managed to balance the schedules and pressures from school and work.

Advanced Java interview questions

Q:In Java, what is the difference between an Interface and an Abstract class?

A: An Abstract class declares have at least one instance method that is declared abstract which will be implemented by the subclasses. An abstract class can have instance methods that implement a default behavior. An Interface can only declare constants and instance methods, but cannot implement default behavior.

Q: Can you have virtual functions in Java? Yes or No. If yes, then what are virtual functions?

A: Yes, Java class functions are virtual by default. Virtual functions are functions of subclasses that can be invoked from a reference to their superclass. In other words, the functions of the actual object are called when a function is invoked on the reference to that object.

Q:Write a function to reverse a linked list p in C++?

A:

Link* reverse_list(Link* p)
{
if (p == NULL)
return NULL;

Link* h = p;
p = p->next;
h->next = NULL;
while (p != null)
{
Link* t = p->next;
p->next = h;
h = p;
p = t;
}

return h;
}

Q:In C++, what is the usefulness of Virtual destructors?

A:Virtual destructors are neccessary to reclaim memory that were allocated for objects in the class hierarchy. If a pointer to a base class object is deleted, then the compiler guarantees the various subclass destructors are called in reverse order of the object construction chain.

Q:What are mutex and semaphore? What is the difference between them?

A:A mutex is a synchronization object that allows only one process or thread to access a critical code block. A semaphore on the other hand allows one or more processes or threads to access a critial code block. A semaphore is a multiple mutex.

C++ object-oriented interview questions

What is pure virtual function?
A class is made abstract by declaring one or more of its virtual functions to be pure. A pure virtual function is one with an initializer of = 0 in its declaration

Q. Write a Struct Time where integer m, h, s are its members
struct Time
{
int m;
int h;
int s;
};

ow do you traverse a Btree in Backward in-order?
Process the node in the right subtree
Process the root
Process the node in the left subtree

Q. What is the two main roles of Operating System?
As a resource manager
As a virtual machine

Q. In the derived class, which data member of the base class are visible?
In the public and protected sections.

Java Web programming interview questions

What is a Servlet?

Answer: Servlets are modules of Java code that run in a server application (hence the name "Servlets", similar to "Applets" on the client side) to answer client requests.

Question2:

What advantages does CMOS have over TTL(transitor transitor logic)? (ALCATEL)

Answer:

• low power dissipation
• pulls up to rail
• easy to interface

How is Java unlike C++? (Asked by Sun)

Answer:

Some language features of C++ have been removed. String manipulations in Java do not allow for buffer overflows and other typical attacks. OS-specific calls are not advised, but you can still call native methods. Everything is a class in Java. Everything is compiled to Java bytecode, not executable (although that is possible with compiler tools).

Question4:

What is HTML (Hypertext Markup Language)?

Answer:

HTML (HyperText Markup Language) is the set of "markup" symbols or tags inserted in a file intended for display on a World Wide Web browser. The markup tells the Web browser how to display a Web page’s words and images for the user.

Question5:

Define class.

Answer: A class describes a set of properties (primitives and objects) and behaviors (methods).

Advanced enterprise Java interview questions

1) What is the purpose of garbage collection in Java, and when is it used?

The purpose of garbage collection is to identify and discard objects that are no longer needed by a program so that their resources can be reclaimed and reused. A Java object is subject to garbage collection when it becomes unreachable to the program in which it is used.

2) Describe synchronization in respect to multithreading.

With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchonization, it is possible for one thread to modify a shared variable while another thread is in the process of using or updating same shared variable. This usually leads to significant errors.

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3) How is JavaBeans differ from Enterprise JavaBeans?

The JavaBeans architecture is meant to provide a format for general-purpose components. On the other hand, the Enterprise JavaBeans architecture provides a format for highly specialized business logic components.

4) In what ways do design patterns help build better software?

Design patterns helps software developers to reuse successful designs and architectures. It helps them to choose design alternatives that make a system reusuable and avoid alternatives that compromise reusability through proven techniques as design patterns.

5) Describe 3-Tier Architecture in enterprise application development.

In 3-tier architecture, an application is broken up into 3 separate logical layers, each with a well-defined set of interfaces. The presentation layer typically consists of a graphical user interfaces. The business layer consists of the application or business logic, and the data layer contains the data that is needed for the application.

JSP interview questions

Q: What are the most common techniques for reusing functionality in object-oriented systems?
A: The two most common techniques for reusing functionality in object-oriented systems are class inheritance and object composition.

Class inheritance lets you define the implementation of one class in terms of another’s. Reuse by subclassing is often referred to as white-box reuse.
Object composition is an alternative to class inheritance. Here, new functionality is obtained by assembling or composing objects to get more complex functionality. This is known as black-box reuse.

Q: Why would you want to have more than one catch block associated with a single try block in Java?
A: Since there are many things can go wrong to a single executed statement, we should have more than one catch(s) to catch any errors that might occur.

Q: What language is used by a relational model to describe the structure of a database?
A: The Data Definition Language.

Q: What is JSP? Describe its concept.
A: JSP is Java Server Pages. The JavaServer Page concept is to provide an HTML document with the ability to plug in content at selected locations in the document. (This content is then supplied by the Web server along with the rest of the HTML document at the time the document is downloaded).

Q: What does the JSP engine do when presented with a JavaServer Page to process?
A: The JSP engine builds a servlet. The HTML portions of the JavaServer Page become Strings transmitted to print methods of a PrintWriter object. The JSP tag portions result in calls to methods of the appropriate JavaBean class whose output is translated into more calls to a println method to place the result in the HTML document.

Java and networking interview questions

QUESTION: What is a JavaBean? (asked by Lifescan inc)

ANSWER: JavaBeans are reusable software components written in the Java programming language, designed to be manipulated visually by a software develpoment environment, like JBuilder or VisualAge for Java. They are similar to Microsoft’s ActiveX components, but designed to be platform-neutral, running anywhere there is a Java Virtual Machine (JVM).

QUESTION: What are the seven layers(OSI model) of networking? (asked by Caspio.com)

ANSWER: 1.Physical, 2.Data Link, 3.Network, 4.Transport, 5.Session, 6.Presentation and 7.Application Layers.

QUESTION: What are some advantages and disadvantages of Java Sockets? (asked by Arashsoft.com)

ANSWER:
Advantages of Java Sockets:

Sockets are flexible and sufficient. Efficient socket based programming can be easily implemented for general communications.

Sockets cause low network traffic. Unlike HTML forms and CGI scripts that generate and transfer whole web pages for each new request, Java applets can send only necessary updated information.

Disadvantages of Java Sockets:

Security restrictions are sometimes overbearing because a Java applet running in a Web browser is only able to establish connections to the machine where it came from, and to nowhere else on the network

Despite all of the useful and helpful Java features, Socket based communications allows only to send packets of raw data between applications. Both the client-side and server-side have to provide mechanisms to make the data useful in any way.

Since the data formats and protocols remain application specific, the re-use of socket based implementations is limited.

QUESTION: What is the difference between a NULL pointer and a void pointer? (asked by Lifescan inc)

ANSWER: A NULL pointer is a pointer of any type whose value is zero. A void pointer is a pointer to an object of an unknown type, and is guaranteed to have enough bits to hold a pointer to any object. A void pointer is not guaranteed to have enough bits to point to a function (though in general practice it does).

QUESTION: What is encapsulation technique? (asked by Microsoft)

ANSWER: Hiding data within the class and making it available only through the methods. This technique is used to protect your class against accidental changes to fields, which might leave the class in an inconsistent state.

Unix/Linux programming interview questions

Question 1: What is the major advantage of a hash table? (Asked by Silicon Magic Corp. people)

Answer: The major advantage of a hash table is its speed. Because the hash function is to take a range of key values and transform them into index values in such a way that the key values are distributed randomly across all the indices of a hash table.

Question 2: What are the techniques that you use to handle the collisions in hash tables?(Asked by Silicon Magic Corp. people)

Answer: We can use two major techniques to handle the collisions. They are open addressing and separate chaining. In open addressing, data items that hash to a full array cell are placed in another cell in the array. In separate chaining, each array element consist of a linked list. All data items hashing to a given array index are inserted in that list.

Question 3: In Unix OS, what is the file server? (Asked by Silicon Magic Corp. people)

Answer: The file server is a machine that shares its disk storage and files with other machines on the network.

Question 4: What is NFS? What is its job?(Asked by Silicon Magic Corp. people)

Answer: NFS stands for Network File System. NFS enables filesystems physically residing on one computer system to be used by other computers in the network, appearing to users on the remote host as just another local disk.

Question 5: What is CVS? List some useful CVS commands.(Asked by Silicon Magic Corp.people)

Anser: CVS is Concurrent Version System. It is the front end to the RCS revision control system which extends the notion of revision control from a collection of files in a single directory to a hierarchical collection of directories consisting of revision controlled files. These directories and files can be combined together to form a software release.
There are some useful commands that are being used very often. They are

cvs checkout
cvs update
cvs add
cvs remove
cvs commit

Unix/Linux administration interview questions

What is LILO?

LILO stands for Linux boot loader. It will load the MBR, master boot record, into the memory, and tell the system which partition and hard drive to boot from.

What is the main advantage of creating links to a file instead of copies of the file?

A: The main advantage is not really that it saves disk space (though it does that too) but, rather, that a change of permissions on the file is applied to all the link access points. The link will show permissions of lrwxrwxrwx but that is for the link itself and not the access to the file to which the link points. Thus if you want to change the permissions for a command, such as su, you only have to do it on the original. With copies you have to find all of the copies and change permission on each of the copies.

Write a command to find all of the files which have been accessed within the last 30 days.

find / -type f -atime -30 > December.files

This command will find all the files under root, which is ‘/’, with file type is file. ‘-atime -30′ will give all the files accessed less than 30 days ago. And the output will put into a file call December.files.

What is the most graceful way to get to run level single user mode?

A: The most graceful way is to use the command init s.
If you want to shut everything down before going to single user mode then do init 0 first and from the ok prompt do a boot -s.

What does the following command line produce? Explain each aspect of this line.

$ (date ; ps -ef | awk ‘{print $1}’ | sort | uniq | wc -l ) >> Activity.log

A: First let’s dissect the line: The date gives the date and time as the first command of the line, this is followed by the a list of all running processes in long form with UIDs listed first, this is the ps -ef. These are fed into the awk which filters out all but the UIDs; these UIDs are piped into sort for no discernible reason and then onto uniq (now we see the reason for the sort - uniq only works on sorted data - if the list is A, B, A, then A, B, A will be the output of uniq, but if it’s A, A, B then A, B is the output) which produces only one copy of each UID.

These UIDs are fed into wc -l which counts the lines - in this case the number of distinct UIDs running processes on the system. Finally the results of these two commands, the date and the wc -l, are appended to the file "Activity.log". Now to answer the question as to what this command line produces. This writes the date and time into the file Activity.log together with the number of distinct users who have processes running on the system at that time. If the file already exists, then these items are appended to the file, otherwise the file is created.

Networking and Unix interview questions

What is UTP?

UTP — Unshielded twisted pair 10BASE-T is the preferred Ethernet medium of the 90s. It is based on a star topology and provides a number of advantages over coaxial media:

It uses inexpensive, readily available copper phone wire. UTP wire is much easier to install and debug than coax. UTP uses RG-45 connectors, which are cheap and reliable.

What is a router? What is a gateway?

Routers are machines that direct a packet through the maze of networks that stand between its source and destination. Normally a router is used for internal networks while a gateway acts a door for the packet to reach the ‘outside’ of the internal network

What is Semaphore? What is deadlock?

Semaphore is a synchronization tool to solve critical-section problem, can be used to control access to the critical section for a process or thread. The main disadvantage (same of mutual-exclusion) is require busy waiting. It will create problems in a multiprogramming system, where a single CPU is shared among many processes.

Busy waiting wastes CPU cycles.

Deadlock is a situation when two or more processes are waiting indefinitely for an event that can be caused by only one of the waiting processes. The implementation of a semaphore with a waiting queue may result in this situation.

What is Virtual Memory?

Virtual memory is a technique that allows the execution of processes that may not be completely in memory. A separation of user logical memory from physical memory allows an extremely large virtual memory to be provided for programmers when only a smaller physical memory is available. It is commonly implemented by demand paging. A demand paging system is similar to a paging system with swapping. Processes reside on secondary memory (which is usually a disk). When we want to execute a process, we swap it into memory.

Explain the layered aspect of a UNIX system. What are the layers? What does it mean to say they are layers?

A UNIX system has essentially three main layers:

� The hardware

� The operating system kernel

� The user-level programs

The kernel hides the system’s hardware underneath an abstract, high-level programming interface. It is responsible for implementing many of the facilities that users and user-level programs take for granted.

The kernel assembles all of the following UNIX concepts from lower-level hardware features:

� Processes (time-sharing, protected address space)

� Signals and semaphores

� Virtual Memory (swapping, paging, and mapping)

� The filesystem (files, directories, namespace)

� Pipes and network connections (inter-process communication)

C++ code examples for job interviews

Q: Write a short code using C++ to print out all odd number from 1 to 100 using a for loop(Asked by Intacct.com people)

for( unsigned int i = 1; i < = 100; i++ )

   if( i & 0x00000001 )

       cout << i<<",";

ISO layers and what layer is the IP operated from?( Asked by Cisco system people)

cation, Presentation, Session, Transport, Network, Data link and Physical. The IP is operated in the Network layer.

3.Q: Write a program that ask for user input from 5 to 9 then calculate the average( Asked by Cisco system people)

A.int main()

{

int MAX=4;

int total =0;

int average=0;

int numb;

cout<<"Please enter your input from 5 to 9";

cin>>numb;

if((numb <5)&&(numb>9))

cout<<"please re type your input";

else

for(i=0;i<=MAX; i++)

{

total = total + numb;

average= total /MAX;

}

cout<<"The average number is"<

return 0;

}

4.Q: Can you be bale to identify between Straight- through and Cross- over cable wiring? and in what case do you use Straight- through and Cross-over? (Asked by Cisco system people)

A. Straight-through is type of wiring that is one to to one connection Cross- over is type of wiring which those wires are got switched

We use Straight-through cable when we connect between NIC Adapter and Hub. Using Cross-over cable when connect between two NIC Adapters or sometime between two hubs.

5.Q: If you hear the CPU fan is running and the monitor power is still on, but you did not see any thing show up in the monitor screen. What would you do to find out what is going wrong? (Asked by WNI people)

A. I would use the ping command to check whether the machine is still alive(connect to the network) or it is dead.

C++ interview questions, some Java

1. In C++, what is the difference between method overloading and method overriding?Overloading a method (or function) in C++ is the ability for functions of the same name to be defined as long as these methods have different signatures (different set of parameters). Method overriding is the ability of the inherited class rewriting the virtual method of the base class.

2. What methods can be overridden in Java? In C++ terminology, all public methods in Java are virtual. Therefore, all Java methods can be overwritten in subclasses except those that are declared final, static, and private.
3. In C, what is the difference between a static variable and global variable? A static variable declared outside of any function is accessible only to all the functions defined in the same file (as the static variable). However, a global variable can be accessed by any function (including the ones from different files).
4. In C, why is the void pointer useful? When would you use it? The void pointer is useful becuase it is a generic pointer that any pointer can be cast into and back again without loss of information.
5. What are the defining traits of an object-oriented language? The defining traits of an object-oriented langauge are:
* encapsulation
* inheritance
* polymorphism

Java software engineering interview questions

Question 1: What is the three tier model?
Answer: It is the presentation, logic, backend
Question 2: Why do we have index table in the database?
Answer: Because the index table contain the information of the other tables. It will
be faster if we access the index table to find out what the other contain.
Question 3: Give an example of using JDBC access the database.
Answer:
try
{
Class.forName("register the driver");
Connection con = DriverManager.getConnection("url of db", "username","password");
Statement state = con.createStatement();
state.executeUpdate("create table testing(firstname varchar(20), lastname varchar(20))");
state.executeQuery("insert into testing values(’phu’,'huynh’)");
state.close();
con.close();
}
catch(Exception e)
{
System.out.println(e);
}
Question 4: What is the different of an Applet and a Java Application
Answer: The applet doesn’t have the main function
Question 5: How do we pass a reference parameter to a function in Java?
Answer: Even though Java doesn’t accept reference parameter, but we can
pass in the object for the parameter of the function.
For example in C++, we can do this:

void changeValue(int& a)
{
a++;
}
void main()
{
int b=2;
changeValue(b);
}

however in Java, we cannot do the same thing. So we can pass the
the int value into Integer object, and we pass this object into the
the function. And this function will change the object.

Network programming interview questions

Question 1: How does the race condition occur?

It occurs when two or more processes are reading or writing some shared data and the final result depends on who runs precisely when.

Question 2: What is multiprogramming?

Multiprogramming is a rapid switching of the CPU back and forth between processes.

Question 3: Name the seven layers of the OSI Model and describe them briefly.

Physical Layer - covers the physical interface between devices and the rules by which bits are passed from one to another.

Data Link Layer - attempts o make the physical link reliable and provides the means to activate, maintain, and deactivate the link.

Network Layer - provides for the transfer of information between end systems across

some sort communications network.

Transport Layer - provides a mechanism for the exchange of data between end system.

Session Layer - provides the mechanism for controlling the dialogue between applications

in end systems.

Presentation Layer - defines the format of the data to be exchanged between applications

and offers application programs a set of data transformation services.

Application Layer - provides a means for application programs to access the OSI environment.

Question 4: What is the difference between TCP and UDP?

TCP and UDP are both transport-level protocols. TCP is designed to provide reliable

communication across a variety of reliable and unreliable networks and internets.

UDP provides a connectionless service for application-level procedures. Thus, UDP is basically

an unreliable service; delivery and duplicate protection are not guareented.

Question 5: What does a socket consists of?

The combination of an IP address and a port number is called a socket.