BSNL GE-JTO Recruitment Examination Paper - 9

BSNL GE-JTO Recruitment Examination

Test Paper - IV

Reactive current through the capacitive load produces -

a) Magnetic field

b) Electric field

c) Supermagnetic field

d) None

One of the following which gives piero-electric effect is -

a) Mu metal

b) PVDF

c) Sapphire

d) Ferrites

PZT piezo- electric materials have -

a) Higher curie temperature

b) Lower curie temperature

c) Absolute temperature

d) None

The residual resistivity of a binary alloy at OK is -

a) The sum of the residual resistivities of the component metals

b) The difference of the residual resistivities of the component metals.

c) The product of the residual resistivities of the component metals

d) Dependent on the concentration of the minor component in the alloy

In active filter circuits, inductances are avoided mainly because they -

a) Are always associated with some resistance

b) Are bulky and unsuitable for miniaturisation

c) Are non-linear in nature

d) Saturate quickly

The depletion layer across a p-n junction lies -

a) mostly in the p-region

b) mostly in the n-region

c) equally to both p and n region

d) entirely in the p-region

The voltage induced in a loop of wire rotating in a strong and steady magnetic field is -

a) pulsating dc

b) dc

c) rectified ac

d) ac

One of the following types of capacitor which is polarized is -

a) Electrolytic

b) Ceramic

c) Paper

d) Mylar

Electric shock is-

a) Always fatal

b) Never fatal

c) Sometimes fatal

d) Always disfiguring

A typical value of filter capacitor for 50 Hz ripple is -

a) 16mF

b) 10F

c) 10mF

d) None

A telephone relay armature is made of material with -

a) High electrical conductivity

b) Low electrical conductivity

c) Negligible conductivity

d) None

Larger the value of filter capacitor -

a) Larger is the peak-peak value of ripple voltage

b) Larger is the peak current in the rectifying diode

c) Longer is the time that current pulse flows through the diode

d) Smaller is the dc voltage across the load

Barrier potential in a P-N junction is caused by -

a) Thermally generated electrons and holes

b) Diffusion of majority carriers across the junction

c) Migration of minority carriers across the junction

d) Flow of drift current

The polarity of VGS for E-only MOSFET is -

a) positive

b) negative

c) zero

d) depends on P or N channel

The following which will serve as a donor impurity in silicon -

a) Boron

b) Indium

c) Germanium

d) Antimony

When bias applied to a vari-cap diode is increased, its capacitance -

a) is decreased

b) is increased

c) remains constant

d) first increases and then decreases.

In case of a bipolar transistor a is -

a) positive and greater than 1

b) positive and less than 1

c) negative and greater than 1

d) negative and less than 1

A BJT is -

a) not very sensitive to radiations

b) very sensitive to radiations.

c) independent of radiations

d) none

An SCR may be considered to be -

a) 2 diodes

b) 3 diodes

c) 4 diodes

d) 5 diodes

For a BJT, under the saturation condition -

a) IC = bIB

b) IC > bIB

c) IC is independent of all other parameters

d) IC <>

In modern MOSFET’s the material used for the gate is -

a) High purity silicon

b) High purity silica

c) Heavily doped polycrystalline silicon

d) Epitaxial grown silicon

Find the Norton,s equivalent of the circuit given below -

When the source in the circuit shown is a sinusoidal source then the input voltage is -

a) 10V

b) 5V

c) 27V

d) 24V

The time constant of the network shown in the given figure is given by -

The voltage transfer ratio of two-port networks connected in cascade may be conveniently obtained from the -

a) product of the individual ABCD matrices of the two networks

b) product of voltage transfer ratios of the two individual networks

c) sum of the Z- matrices of the two networks

d) sum of the h – matrices of the two networks

When a network has response with time as shown in fig. then which one of the following diagrams represents the location of the poles of this network ?

For the network shown in the given fig. the ratio is -

An attenuator drops a 10V signal to 50mv in an experiment. The loss in decibels is -

a) –40dB

b) –6dB

c) –55dB

d) –60dB

When the network has 10 nodes and 17 branches then the number of different node pair voltages would be -

a) 7

b) 9

c) 10

d) 45

The circuit shown in the following fig. will act as an ideal current source with respect to terminals A and B when frequency is -

a) zero

b) 1rad/s

c) 4rad/s

d) 16rad/s

When a short vertical grounded antenna is required to radiate at 1MHz and the effective height of the antenna is 30 m then the calculated value of the radiation resistance is -

a) 1.58 W

b) 158 W

c) 15.8 W

d) None of these

Shannon’s law relates -

a) antenna gain to bandwidth

b) frequency to antenna gain

c) antenna gain to transmission losses

d) information carrying capacity to S/N ratio

One of the following modes which has the characteristic of attenceation becoming less as the frequency is increased and is attractive at microwave frequencies of circular cylindrical wave guides is -

a) TE1 mode

b) TM01 mode

c) TE01 mode

d) Higher order mode

For a transmission line, the propogation constant, for a TEM wave travelling in it is given by (Where the symbols have the usual meanings ) -

a) [ (R+jwL) (G+jwc)]

b) [ R+jwL) (G+jwc)] ½

c) [ (R-jwL) (G + jwc) ] ½

d) [(R-jwL) ( G+jw2c)]1/3

The advantages of wave guides over co-axial lines would include which of the following features-

1. Easier to use 2. lower power losses

3. Higher operating frequencies possible

a) 1 and 2

b) 1 and 3

c) 2 and 3

d) 1,2 and 3

When a 75 ohm transmission line is to be terminated in two resistive loads R1 and R2 such that the standing pattern in the two cases have the same SWR , then the values of R1 and R2 (in ohms) should be -

a) 250 and 200 respectively

b) 225 and 25 respectively

c) 100 and 150 respectively

d) 50 and 125 respectively

The degenerate modes in a wave guide are characterized by -

a) Same cut off frequencies but different field distribution

b) Same cut off frequencies and same field distributions

c) Different cut off frequencies but same field distributions

d) Different cut off frequencies and different field distributions

A TEM wave impinges obliquely on a dielectric-dielectric boundary with Er1=2 and Er2=1, the angle of incidence for total reflection is -

a) 30 0

b) 60 0

c) 45 0

d) 90 0

The radiation pattern of Hertzian dipole in the plane perpendicular to the dipole is a -

a) Null

b) Circle

c) Figure of eight

d) None of the above

40. Permeance is the -

a) square of reluctance

b) reluctance

c) reciprocal of the reluctance

d) cube of the reluctance.

One of the following which is an active transducer is -

a) Photoelectric

b) Photovoltaic

c) Photo-conductive

d) Photo emission

The wein bridge uses only -

a) Inductors

b) Capacitors

c) Resistors

d) Capacitors and Resistors.

The greater the value of Q -

a) higher will be the bandwidth of the resonant circuit.

b) smaller will be the bandwidth of the resonant circuit.

c) nothing can be said)

d) none.

The most serious source of error in a) c) bridge measurement is -

a) eddy currents

b) leakage currents

c) residual imperfectness

d) stray fields.

Moving iron instruments -

a) have a linear scale

b) do not have a linear scale

c) both a and b)

d) none.

If accuracy is the main consideration, which one of the following voltmeters should one select -

a) 100 v ; 2 mA

b) 100 v ; 100 ohm/volt

c) 100 v ; 1mA

d) 10,000 v ; 10 mA

In dc tacho generators used for measurement of speed of a shaft, frequent calibration has to be done because -

a) the contacts wear off

b) the strength of permanent magnet decreases with age

c) the armature current produces heating effect

d) there is back emf.

Ideal transformer cannot be described by -

a) h parameters

b) ABCD parameters

c) G parameters

d) parameters

Consider the following statements -

A3- phase balanced supply system is connected to a 3 phase unbalanced load) Power supplied to this load can be measured using

1. Two wattmeters

2. One wattmeter

3. Three wattmeters

Which of these statements is/are correct?

a) 1 and 2

b) 1 and 3

c) 2 and 3

d) 3 alone

The function of the reference electrode in a pH meter is to -

a) Produce a constant voltage

b) Provide temperature compensation

c) Provide a constant current

d) Measure average pH value

Match the column A (Devices) with column B (Characteristics) and select the correct answer by using the codes given below the column -

Column A Column B

A) BJT 1. Voltage controlled negative resistance

B) MOSFET 2. High current gain

C) Tunnel diode 3. Voltage regulation

D) Zener diode 4. High input impedance

Codes :

A B C D

a) 1 4 2 3

b) 2 4 1 3

c) 2 3 1 4

d) 1 3 2 4

A thyristor during forward blocking state is associated with.-

a) large current , low voltage.

b) low current , large voltage.

c) medium current , large voltage

d) low current, medium voltage.

In controlled rectifiers, the nature of load current i.e. whether load current is continuous or discontinuous -

a) does not depend on type of load and firing angle delay

b) depends both on the type of load and firing angle delay

c) depends only on the type of load)

d) depends only on the firing angle delay.

A single phase voltage controller feeds power to a resistance of 10 W . The source voltage is 200 V rms. For a firing angle of 900 , the rms value of thyristor current in amperes is -

a) 20

b) 15

c) 10

d) 5

In the performance of single phase and three phase full converters the effect of source inductance is to

a) reduce the ripples in the load current -

b) make discontinuous current as continuous

c) reduce the output voltage

d) increase the load voltage.

The cycloconverters (CCs) require natural or forced commutation as under -

a) natural commutation in both step up and step down CCs

b) forced commutation in both step up and step down CCs

c) forced commutation in step up CCs

d) forced commutation in step down CCs

Power transistors are more commonly of -

a) silicon npn type.

b) silicon pnp type.

c) silicon nnp type.

d) silicon npp type.

C is a -

a) Middle level language

b) High level language

c) Low level language

d) None of above

What will be output of program

main ( )

{ int i ;

print f ("Enter value of i");

scant ("%d", & i);

if ( i = 5 )

print f ("you entered 5");

else

print f ("you entered %d", i ); }

if user entered 100 then

a) 5

b) 100

c) 1005

d) None

(7F)16 + (BA)16 = (?)16-

a) 481

b) 139

c)–481

d) –139

Two’s complement of 3 bit nonzero linory number is some or original number is all bits accepts-

a) MSB are zeros

b) LSB are zeros

c) MSB are ones

d) LSB are ones.

The schematic circuits of RTL NOR gate is-

Transistors with high frequency have -

a) Thick base

b) Thin base

c) Some other feature

d) None of the above

Telephone traffic is specified in terms of -

a) Average waiting time

b) Grade of service

c) Peak waiting time

d) Erlangs

In a Hartley oscillator -

a) Necessary phase relation is obtained by connecting grid and plate electrodes to the opposite ends of the tuned circuit.

b) The mutual inductance must have the appropriate polarity.

c) Both grid circuit and plate tuned circuit offer inductive reactance

d) None of the above

The condenser C is charged in a bootstrap sweep generator -

a) Linearly but the discharge is non linear

b) Non linearly but the discharge is linear

c) Linearly and the discharge is linear

d) Non linearly and the discharge is non linear

In an audio amplifier audio signals become garbled and hence difficult to understand when an ac input current is large enough to drive the output to -

a) saturation only

b) Cut off only

c) Either saturation or cut off

d) A value off the load line

Five 1 bit registers are referred as -

a) Flags

b) Slags

c) Tags

d) None of the above

Next binary number after 0,1, 10, 11 is -

a) 12

b) 101

c) 100

d) 110

Identify coincidence logic circuit in the following –

a) b)

c) d)

The output analog voltage Vo is given by -

If an inverter is placed at the input to an SR flip flop, the result is -

a) T flip flop

b) D flip flop

c) JK flip flop

d) BCD decade counter

See the Root locus diagram of a system and the following statements :-

1. The open loop system is a second order system.

2. The system is over damped for

3. The system is absolutely stable for all value of R.

Which of these statements are correct?

a) 1, 2, & 3

b) 1 and 3

c) 2 and 3

d) 1 and 2

For the transfer function G(S)H(S) = the phase cross over frequency is -

a) 0.5 rad/sec

b) 0.707 rad/sec

c) 1.732 rad/sec

d) 2 rad/sec

If the open loop transfer function of the system is G(S) H(S) =

then a closed loop pole will be located at S = -12 wher the value of K is -

a) 4355

b) 5760

c) 9600

d) 9862

Considering the following open loop transfer function -

The correct sequence of these systems in increasing order of the time taken for the unit step response to settle is –

a) 1, 2, 3

b) 3, 1, 2

c) 2, 3, 1

d) 3, 2, 1.

Considering unit feed back control system in the given figure, the ratio of time constant of closed loop response to open loop response will be -

a) 1: 1

b) 2 :1

c) 3 : 2

d) 2 : 3

Angle subtended by earth at geostationary communication satellite is -

a) 17.340

b) 51.40

c) 1200

d) 600

For data transmission phase modulation is commonly used because -

a) Phase can be varied from +1800 to -1800

b) It is resistant to the effects of noise.

c) Demodulation is very easy

d) It gives highest data rates that can be transmitted over a given channel.

Several channels are interleaved and then transmitted together is known as –

a)Frequency division multiplex

b) Time division multiplex

c) A group

d) A super group

Identify the wrong statement-

The radar cross section of a target -

a) Depends on the frequency used

b) May be reduced by special coating of the target

c) Depends on the aspect of a target, if this is non spherical

d) Is equal to the actual cross-sectional area for small targets.

Considering following parameters -

1. Loss in the media) 2. Permeability of the media) 3. Frequency of the wave 4. Velocity of the wave. Which of these parameters are responsible for the change of phase of a propagating electromagnetic wave?

a) 1, 2, and 3

b) 2, 3 and 4

c) 1, 3 and 4

d) 1 and 4

In super heterodyne receivers double spotting is caused by -

a) poor front-end rejection

b) misalignment of receiver

c) detuning of one or more IF stages.

d) non functioning of AGC

The number of lines per field in the United States TV system is -

a) 262 1/2

b) 525

c) 30

d) 60

In a TV receiver the color killer -

a) cuts off the chroma stages during monochrome receivers.

b) ensures that no color is transmitted to monochrome receivers

c) prevents color overloading

d) makes sure that the color burst is not mistaken for sync pulses, by cutting off reception during the back porch.

The nominal capacitance of a coaxial RF cable is of 40 pF/m and the characteristic impedance of 50W. The inductance of the cable is-

a) 1mH/m

b) 10 mH/m

c) 0.1 mH/m

d) 0.01 mH/m

Transmission of wave through Dominant mode is -

a) distortion less transmission

b) generates undesirable harmonic distortion

c) having loss of power

d) None of above.

Lower the standing wave ratio (SWR) -

a) Greater mismatch error

b) Lower mismatch error

c) No effect on matching

d) Moderate mismatch error

In klyrtron oscillator for getting wide range of oscillations resonators should be -

a) Critically coupled

b) Under coupled

c) Over coupled

d) No coupling required

The critical frequency is always -

a) Lower than maximum usable frequency

b) Equal to maximum usable frequency

c) Higher than maximum usable frequency

d) None of above

The PIN diode based on -

a) Nonlinear resistance

b) Nonlinear reactance

c) Negative resistance

d) Controllable impedence

Which antenna having circular polarization -

a) Horn antenna

b) Lens antenna

c) Helical antenna

d) Discone antenna

The i/p S/N ratio of system is 50 and the o/p S/N ratio is 5 the noise figure is -

a) 250

b) 55

c) 10

d) 45

In the 8085 mP, the RST 6 instruction transfers the program execution to the following location -

a) 30 H

b) 24 H

c) 48 H

d) 60 H

In instruction cycle first operation is -

a) Memory read

b) Address read

c) Opcode fetch

d) Data read

CMP instruction comes under group -

a) Data transfer

b) Branching operations

c) Machine control operation

d) Logical operations.

In which logic operation does not effect any flags -

a) ANA B

b) ORA B

c) XRI A2H

d) CMA

What happen when CALL instruction executed -

a) Data retrieved from stock to register

b) Data from register saved on the stock.

c) 16 bit address of instruction saved on stock

d) 16 bit address from stock retrieved)

The mark status of mark able interrupts is defined according to content of -

a) stack pointer.

b) HL register .

c) Program counter

d) Accumulator

The decoder is a logic ckt that -

a) Amplifies the current or power at i/p.

b) Identifies each combination of the signals present at i/p

c) Provides appropriate code as o/p for each i/p signal

d) Both b & c)

The young man was quickly promoted when his employers how --------------- he was -

a) indigent

b) indifferent

c) assiduous

d) cursory.

As letter is alphabet so zodiac is -

a) almanac

b) beacon

c) sign

d) signal.

What is the correct meaning of prudish.?

a) careful

b) fast

c) God

d) brave

Pick out the odd matching with reference to number -

a) woman – women.

b) hair – hairs

c) child – children.

d) foot – feet.

Choose the phrase that is most nearly similiar in meaning to the word given below-

Abut is

a) Stimulate

b) Grasp

c) Oppose

d) Adjoin

The highest mountain peak in Indian Territory is -

a) Mount Everest

b) Kanchenjunga

c) Nanda Devi

d) Mount Kailash

German silver is an alloy comprising -

a) Copper, Nickel and Zinc

b) Silver, copper and Zinc

c) Silver Nickel and Zinc

d) Nickel, Zinc and Lead

Mughal Emperor Bahadur Shah Zafar’s mausoleum is in -

a) Delhi

b) Lahore

c) Yangon

d) Agra

On which date the World Trade Centre in New York and Pentagon in Washington d)C was attacked by terrorist -

a) 12 September 2001

b) 11 September 2001

c) 11 July 2001

d) 20 December 2001

India defeats South Africa in the finals of the inaugural champions challenge Hockey Tournament in Kualalumpur by -

a) 4-2

b) 2-0

c) 3-2

d) 2-1

Which planets in the solar system are known as ‘Inferior Planets’ -

a) Earth and Mars

b) Earth and Mercury

c) Mars and Mercury

d) Mercury and Venus.

The largest Stupa in Southern India is at -

a) Nellore

b) Amravati

c) Tanjore

d) Kozhikode

The new chairman and Managing Director of Industrial Finance Corporaton of India (IFCI) is -

a) Mr. Vishwanath Prasad Singh

b) Mr. Jitendra Patil

c) Mr. Ragh

d) Mr. Shubhash chand Jain

Which one is the latest among rock-cut temples?

a) Ajanta

b) Ellora

c) Elephanta

d) All originated in the same period)

Number of organisations government ban in Jammu and Kashmir and the North East under the new ordinance ‘POTO’ is -

a) 20

b) 21

c) 22

d) 23

In bed of which river does Badrinath shrine stand?

a) Ganga

b) Mandakini

c) Alakananda

d) Bhagirathi

The nerve endings for the sense of sight are located in the part of the eye called the -

a) Cornea

b) Sclera

c) Iris

d) Retina

Fundamental duties were introduced in the constitution by the -

a) 40th Amendment

b) 42nd Amendment

c) 43rd Amendment

d) 44th Amendment

The Khalsa Panth was founded by -

a) Guru Hargovind

b) Guru Nanak Dev

c) Guru Tegh Bahadur

d) Guru Govind singh

Number of countries involved in international fleet review hosted by India is -

a) 27

b) 28

c) 29

d) 30

BSNL GE-JTO Recruitment Examination - Test Paper - III Paper - 8

BSNL GE-JTO Recruitment Examination

Test Paper - III

Of the following bridges the one which can be used for the measurement of dielectric loss of a capacitor is –

a.) Schering bridge

b..) Heaviside campbell equal ratio voltage

c) Owen bridge

d.) Anderson bridge

LBDT is uses as a –

a). Displacement transducer

b.) Pressure transducer

c.) Temperature

d.) Any of the above

Polarization is a measure of -

a.) Dielectric constant per unit volume.

b. )Voltage gradient to produce electrical breakdown

c.) Product of charge and distance

d.)Excess charge density

Compared to the inductive type of transducer, capacitive transducer is superior for the measurement of displacement because of -

a.)Absence of non-linearity

b.) High frequency response

c.) Small size

d.) High accuracy

An incremental model of a solid state device is one which represents the –

a.) ac property of the device at the desired operating point

b. )dc property of the device at all operating points

c.) Complete ac and dc behaviour of the device at all operating points

d.)ac property of the device at all operating points.

The ac resistance of a forward biased p-n junction diode operating at a bias voltage ,V, and carrying current ‘I’ is –

a. )Zero

b. )a constant value independent of Vand I

c.)

d.

A meter is shielded with a soft iron to –

a. )Prevent damage from rough use

b.) Keep moisture out of movement

c. )Protect meter movement from stray magnetic fields

d.) Achieve all of the above

A capacitor that has been connected across a battery for comparatively long time becomes–

a. )Charged

b.) Discharged

c.) Short - circuited

d.) Defective

The charge on the plates of a capacitor is given by the expression –

a.) Q = VI

b.) Q = IR

c.) Q = CV

d.) Q = IC

Silicon steel used for electrical purposes has silicon percentage of –

a. )0.5

b.) 2.5

c.) 3.4

d). None

The feature of VTM is its –

a. )Low input impedance

b. )Low power consumbtion

c. )The ability to measure wider ranges of voltage and resistances

d). None

In an N-type semiconductor, the position of the fermi level –

a. )Is lower than the centre of the energy gap

b.) Is at the centre of the energy gap

c.)Is higher than the centre of the energy gap

d. )Can be anywhere depending upon the doping concentration

A JFET can operate in –

a.) depletion and enhancement model

b. )depletion mode only

c. )enhancement mode only

d.) neither enhancement nor depletion mode

Consider the following semiconductor diodes –

a. )Germanium diode

b.)Silicon diode

c.) Tunnel diode

d.) Schottky diode

A diode with a PIV of 50V is likely to break down when rectifying 50v ac supply because –

a.) it is made of defective material

b.) it is incorrectly connected to the supply

c.) peak value of ac supply exceeds the PIV value

d. )ac supply is of extremely high frequency.

The set of transistor characteristics that enables a to be determined directly from the slope is –

a.) CE transfer characteristics

b. )CE output characteristics

c.) CB transfer characteristics

d.) CB input characteristics

For an N-channel JFET, the drain voltage has to be –

a.) positive with respect to the source

b.) negative with respect to the source

c.) uncharged with respect to the source

d.)none

The SCR is often employed as a –

a. )Source-controlled switch

b. )Drain-controlled switch

c.) Gate-controlled switch

d) None

An oscilloscope has an input impedance consisting of 1MW and 20pF in parallel. A high impedance probe connected to the input of this oscilloscope has a 10MW series resistance, this 10MW resistance –

a.) Need not be shunted

b.) Should be shunted by a 2pF capacitor

c.) Should be shunted by a 20pF capacitor

d. )Should be shunted by a 200pF capacitor

Compared to silicon, gallium arsenide (GaAs) has –

a. )Easier to grow crystals since the vapour pressure of arsenic is high

b. )Higher optolectronic conversion efficiency

c.) Both a and b

d). None

When the network shown in the fig draw a current I and if the ends ab are shorted, the current drawn would be –

a.) I

b.) I\ 4

c.) 4 I

d.) 2 I

When all the resistances in the circuit are of one ohm each, then the equivalent resistance across the points A and B will be –

a.)1W

b.) 0.5W

c.) 2W

d). 1.5W

Of the following periodic waveforms the one having only odd harmonics of sinusoidal waveform is-

a. )1 and 2

b.) 1 and 3

c. )1 and 4

d. )2 and 4

When in the network shown in the given fig, the switch K is dosed at t = 0 with the capacitor uncharged then the value for at t = 0+ will be –

a. )100 amp./sec.

b. )–100 amp./sec.

c. )1000 amp./sec.

d. )–1000 amp./sec.

For the circuit shown in the given figure, the voltage VAB is –

a. )6V

b.)10V

c. )25V

d. )40V

In the network shown in the given fig. current i = 0 when E = 4V, I = 2A and I = 1A when E = 8V, I = 2A. The Thevenin voltage and the resistance into the terminals AB are –

a. )4V, 2W

b.) 4V, 4W

c.) 8V, 2W

d.) 8V, 4W

The effective resistance between the terminals A and B in the circuit shown in the fig. is –

a.) R

b.) R-1

c.) R/2

d.) 6/11 R

When in a two terminal network, the open circuit voltage measured at the given terminals by an electronic voltmeter is 100V and a short circuit current measured at the same terminals by an ammeter of negligible resistance is 5A then if a resistor of 80W is connected at the same terminal, then the current in the load resistor will be –

a. )1A

b.) 1.25A

c). 6A

d.) 6.25A

If for the network shown in the following fig. the value of Z(s) is then the value of C and R are respectively –

In Faraday’s induction phenomenon, a changing magnetic field is accompanied by an electric field. Which of the following equation or equations represents it-

The electric potential due to an electric dipole of length L at point distance r away from it will be doubled if the -

a. ) Length L of the dipole is doubled

b. ) r is doubled

c. ) r is halved

d ) L is halved

When a particular mode is excited in a waveguide there appears an extra electric component in the direction of propogation . The resulting mode is

a. ) Longitudinal electric

b. ) Transverse electromagnetic

c. ) Transverse magnetic

d ). Transverse electric

When for a transmission line the open circuit and short circuit impedance are 20W and 5 W respectively then the characteristic impedance of the line is -

a. ) 100 Ohms

b ). 50 Ohms

c. ) 25 Ohms

d. ) 10 Ohms

In an ideal transmission line with matched load, the voltage standing wave ratio and reflection coefficient are respectively -

a. ) 1 and 1

b ). infinity and 1

c ) infinity and 0

d. ) 1 and 0

When an electric charge of 100 coulombs is enclosed in sphere of radius 100 m then the electric displacement density ( in coulomb / m2) D is –

a. ) 0.0833

b ). 0.833

c. ) 1.666

d. ) 10

For the dominant mode in a rectangular wavelength with breadth 10 cm, the guide wavelength for a signal of 2.5 GHz will be -

a. ) 12 cm

b. ) 15 cm

c. ) 18 cm

d. ) 20 cm

When the phase velocity of an electromagnetic waves depends on frequency in any medium, the phenomenon is called-

a. ) Scattering

b. )Polarization

c. ) Absorption

d. ) Dispersion

Antennas commonly used for microwave links are -

a. ) Loop antenna

b. ) Log-periodic antennas

c. ) Paraboloidal dishes

39. One of the following instrument which may be used to measure the optical activity of compounds is –

a. )Infrared spectrometer

b. ) Atomic absorption spectrometer

c. ) Polarimeter

d. ) Flouroscope

Schering bridge measures –

a. )Capacitance dielectric loss

b. ) Inductance

c. )Resistance

d. ) Mutual inductance

When a square wave is fed to an RC circuit, then –

a. ) voltage across R is square and across C is not square

b. ) voltage across C is not square and across R is not square

c. ) voltage across both R and C are square

d. ) voltage across both R and C are not square

The time constant of the RC circuit is –

a. ) less than the time period of the input square wave.

b ). much larger than the time period of the input square wave.

c. ) equal to the time period of the input square wave.

d ). none

Harmonic distortion for each frequency can be obtained by harmonic analyser of the –

a. )heterodyne type

b. ) tuned circuit type

c. ) fundamental suppression type`

d. ) bridge circuit type.

A three phase wattmeter requires –

a ). only two current coils and two pressure coils

b. )only one current coil and two pressure coil

c. ) only two current coils and one pressure coil

d. ) only current coil

A low pass filter circuit is basically –

a. ) a differentiating circuit with low time constant

b. ) a differentiating circuit with large time constant.

c. ) an integrating circuit with low time constant.

d. )an integrating circuit with large time constant.

If the differential pressure in restriction type flow measuring devices is then the flow will be proportional to –

When a system is represented by the transfer function then the dc gain of this system is –

a.) 1

b.) 2

c.) 5

d.) 10

Silicon based semiconductor device called thyristor was first fabricated by –

a). Jell laboratories in U.S.A

b). Maxwell laboratories in U.S.A

c.) Bell laboratories in U.S.A

d). GEC laboratories in U.S.A

A semiconductor based temperature transducer has a temperature coefficient of –2500mV/0C. This transducer is indeed a –

a.)Thermistor

b.) Forward biased pn junction diode

c. )Reverse biased pn junction diode

d.) FET

Which of the followings pairs of Telemetry situations and Modulation techniques and conditions is correctly matched-

a. )Pulse amplitude modulation Low amplitude signals

b. )Pulse position modulation For short distance when power is enough

c.) Pulse width modulation Power to be spent in telemetry is required to be low

d.) Pulse code modulation. Minimisation of interference effects.

The SCR ratings di/dt in A/m sec and dv/dt in n/m sec, may vary, respectively between-

a.) 20 to 500, 10 to 100

b. )both 20 to 500

c.) both 10 to 100

d.) 50 to 300, 20 to 500

Match the given controlled rectifiers with 50 Hz supply

a. )1 phase full converter with source inductance

b. )3 phase full converter

c.)3 phase semiconductor

d. )3 phase halls wave converter

For natural or forced commutation the cyclo converters (CCs) requires as under.

a) natural commutation in both step up and step down CCs

b.) forced commutation in both step up and step down CCs

c.) forced commutation in step up CCs

d). forced commutation in step down CCs

The peak inverse voltage in ac to dc converter system is highest in-

a). single phase full wave mid point converter

b). single phase full converter

c) 3 phase bridge converter

d). 3 phase half wave converter.

A single phase full converter feeds power to RLE load with R = 6 W L = 6 MH and E = 60 V. The ac source voltage is 230 V, 50 Hz, For continuous conduction, the average value of load current for a firing angle delay of 50 is

a.)12.181 A

b). 14.81 A

c). 16.76 A

d.) 32.40 A

Which one of the following is the Fourier transform of the signal given in fig. B if the Fourier transform of the signal in fig A is given by -

What is 215 complement of 00011100-

a.) 11100011

b.) 10001100

c.) 11100100

d.) 10000111

In C programming a expression contains relational operators, assignment operators and arithmetic operators if parentheses is absent then execution follows

a.) assignment, relational, arithmatic

b.) arithmatic, relational, assignment

c.) relational, arithmatic, assignment

d.) assignment, arithmatic, relational

In semiconductor memory information stored in form-

a.) binary

b.) hexadecimal

c.) octal

d.) ASCII

i\p to Not gate gives o/p as-

a ) inversion of some bits

b.) 2’s complement of i\p

c.) 1’s complement of i\p

d.) o/p is some as i\p

A negative logic means-

a .)logic 0 and 1 are represented by a +ve voltage respective

b). logic 0 and 1 are presented as –ve and +ve voltage

c. )logic 0 voltage is higher than logic 1 voltage level

d.) logic 0 voltage is lower than logic 1 voltage level

For designing D flip flop from SR FF a circuit is aloud at 01p of SR FF is-

a.) AND

b.) OR

c.) NOR

d.) NOT

The transistor shown in fig is

a. ) Silicon, NPN with Ic = 0.5 mA

b.) Silicon PNP with Ic = 0.5 mA

c.) Germanium PNP with IE = 0.5 mA

d.) Germanium NPN with Ic=0.5 mA

A 20,000 Ohms per volt meter will deflect full-scale with a current of -

a.) 50 mA

b.) 50 mA

c.) 100 mA

d.) 1000 mA

A plate modulated class –CRF power amplifier produces 100 KW of radiated power at 100 % modulation. The modulating audio amplifier supplies approximately -------- kW of this power-

a.)50

b).33

c).22

d).11

An amplifier without feedback has a distortion of 15 % and gain of 40. When 10% negative feedback is applied the distortion will become-

a.) 50 %

b). -45 %

c). 3%

d). -5%

MODEM implies-

a.)Modulator at transmitting side and ditector at the receiving side

b.)Which deals with analog signals and shows digital information

c.)Analog to digital at transmitting side and digital to analog at a receiving side

d).A device which deals with digital signals only

Twisted ring and ring counters are examples of –

a. )Synchronous counters

b.) Asynchronous counters

c.) both a and b

d.) None of the above

Specify Non characteristic flip flop in the following –

a.) The outputs are complement of each other

b.) The flip flop has two input signals

c.) The flip flop has two output signals

d). The flip flop is a bistable devise with only two stable states

The voltage obtained when digital input is 001 is a 3 bit R-2R ladder DIA converter is-

a.) VR/22

b.) VR/21

c.) VR/23

d.) none of the above

Identify NOT an octal number-

a.) 19

b). 15

c.) 77

d.) 101

The set of binary digits 01000100 represent,s-

a.) number 6810 in a pure binary computer

b.) number 44 in 8421 BCD code

c) Both a and b

d.) None of the above

The system matrix of a continuous time system, described in the state variable form is –

The system is stable for all values of x and y satisfying –

a.)x <>

b). x <>

c. )x > 1/2 , y >0

d.) x <>

The break away and break in point in the root locus for open loop transfer function G(S) H(S) = are located respectively at –

a). –2 and -1

b). –2.47 and –3.77

c.) –4.27 and –7.73

d.) –7.73 and –4.27

The transfer function for the given system shown in figure is –

The type and order of the system whose Nyquist plot is shown in fig is-

a.)0.1

b.) 1,2

c.) 0,2

d). 2,1

The overall transfer function in a second order is given by-

Its resonant frequency is -

a.) 2

b.)

c).

d.) 3

The detection of an AM waveform in an Envelope –

a.)One side band and full amplitude carrier are needed

b.) Both side bands and full amplitude carrier are needed

c). Only two side bands are needed

d). Upper side band and part of carriers are needed

Satellite used for intercontinental communication is known as –

a.) Comsat

b). Dom sat

c.) Mari sat

d). Intelsat

Mark out non submarine cable –

a. )TAT – 7

b.) INTELSAT V

c.) ATLANTIS

d. )CANTAT 2

The capacity of an analog communication channel with 4kHz bandwidth and 15 dB SNR is approximately-

a). 20,000 bps

b). 16,000 bps

c.) 10,000 bps

d.) 8,000 bps

The blind speed of an MTl radar can be avoided by changing the-

a.) Carrier frequency

b.) Pulse repetition frequency

c. )Antenna rotation rate

d.) Transmitted power

The output voltage in a feedback series regulator circuit is regulated by controlling the-

a.) Magnitude of the input voltage

b.) Gain of the feedback transistor

c.) Reference voltage

d.) Voltage drop across the series pass transistor

Indicate the signal not transmitted in colour TV-

a.) Y

b.) Q

c.) R

d.) I

As frequency of singal increases-

a.) Directivity increases & beam width increases

b.) Directivity & beam width decreases

c.) Directivity increases & beam width decreases

d.) Directivity decreases & beam width increases

The number of hardware interupts (which require an external signal to interrupt) present in on 8085 mP are

a). 1

b). 4

c.) 5

d.) 13

Highest priority interupt is-

a. )INTR

b. )RST 7.5

c. )RST 6.5

d. )TRAP

One instruction cycle means-

a. )Time require to execute set of instructions

b. )Time require to execute one instruction

c.) Time require to complete one operation of accessing memory, or I/o

d.) None of above

If the clock freq. is 5 mH3 how much time is required to execute on instruction of 18 T-states-

a. )3.6 msec.

b.) 36 m sec.

c.) 36 m sec.

d.) 36 sec.

In data transfer operation which flog get affected-

a. )zero flog

b. )carry flog

c. )sign flog.

d.) none

CMP instruction comes under group -

a. )Data transfer

b. )Brouching operations

c). Machine control operation

d.) logical operations

The logic operation-

a.) are performed in relation to content of Accemce lotor

b).can be performed derectly with content of the register.

c.)are performed without content of a

d.)none of above.

What happen when PUSH instruction executed -

a.) data retrieved from stock to register

b.) data from register saved on the stock.

c.) 16 bit address of instruction saved on stock.

d.) 16 bit address from stock retrieved

SIM stands for-

a. ) serial interface memory

b.) set interrupt mosk

c. ) set if minus

d.) set internal memory

Maximum clock frequency required to operate 8085-

a. )2 MHz

b.) 3 MHz

c) 6 MHz

d. )9 MHz

ASCII code is-

a). 7 bit

b). 8 bit

c.)16 bit

d.) 32 bit.

In memory mapped I/O address lines are-

a. ) 8

b.) 16

c.) 32

d.) 64

The parity bit adding technique is used for -

a. )Indexing

b. )Coding

c. )Error detection

d. )Controlling

A demultiplexer-

a. )has multiple i/p and single o/p

b.) has single i/p and multiple o/p

c.) has multiple i/p and multiple o/p

d.) has single i/p and single o/p

Subroutines are useful-

a. )to reduce storage requirements

b.) to increase programming speed and reduce storage

c.) most applications are same

d.) but increases expense

As daring goes with temerity same way clear-sighted with –

a. )Perspicacity

b.) Impulsiveness

c.)Energy

d. )Clemency

A man who visits his friend is a –

a. )Host

b. )Guest

c. )Master

d.) Owner

Zealot is –

a. )beginner

b.) Patron

c.) fanatic

d.) Murderer

Give the plural of ‘Mouse’ –

a. )Mouse’s

b). Mice

c). Mouse

d). None

Find the part of speech of the underlined word –

Shama and Radha were playing together.

a. )Preposition.

b. )Noun

c. )Conjunction.

d). Verb.

Which of the following is not one of the multiple names of ganesha?

a). Vinayaka

b). Lambodra

c.) Ekadanta

d.) Vighneshwara

e. )all of the above

If a man weighs 60 Kilograms on earth, how much will be his weight on the moon?

a. )50 kg

b. )40 kg

c. )20 kg

d. )10 kg

The only Indian star selected for waxing at the famous Madame Tussaud’s wax is-

a. )Salman Khan

b. )Amitabh Bachan

c. )ShahRukh Khan.

d. )Raj Kapoor

Rate of gowth of per capita income in India drops down to – percent in 2000-2001-.

a. )5.3 percent

b. )3.5 percent

c. )4.8 percent

d. )8.4 percent

Ascorbic acid is the chemical name of-

a. )Vitamin A

b. )Vitamin B

c. )Vitamin C

d.) Vitamin D

All India Muslim League was founded by-

a. )Nawab Slimullah Khan

b. )Sir Mohd Iqubal

c.) Sir syed Ahmed Khan

d.) Moulana Shaukat Ali

Red Blood corpuscles are formed in-

a. )Marrow

b.) Kidney

c). Liver

d). heart

The southern most tip of India is in-

a. )Lakshadweeep

b.) Kanya Kumari

c. )Andaman and Nicobar Islands

d. )Rameswaram

The first bowler in cricket history to take 500 test wickets is-

a.) Imran Khan

b). Courtney Walsh

c). Shane Warne

d.) Muttiah Murlidharan

President of the National Consumer Disputes Redress al Commission (NCDRC) is-

a.) Mr. D.C Wadhwa

b). Mr. A. P Wadhwa

c.) Mr. A. C Wadhwa

d.) Mr. D. P Wadhwa

C.V. Raman got Nobel Prize for-

a. )Themodynamics

b.) Quantum theory

c. )Optics and spectroscopy

d.) Nuclear Physics

First governor general of Bengal-

a). Lord Clive

b.) Lord warren Hastings

c. )Lord Lytton

d.) Lord Ripon

The slogan “Do or Die” is associated with-

a.) Subhash Chandra Bose

b.) Gandhigi

c.) Harijan

d.) Satyagraha

Champaran is in the state of-

a). Gujarat

b). Maharashtra

c.) Bihar

d). Madhya Pradesh

These tribes are found in central Asia-

a. )Garos

b. )Kirghiz

c.) Lushai

d). Santhals

BSNL GE-JTO Recruitment Examination - Test Paper - II Paper - 7

BSNL GE-JTO Recruitment Examination

Test Paper - II

If the voltage applied across a capacitance is triangular in waveform then the waveform of the current is-
a) Triangular

b) Trapezoidal

c)) Sinusoidal

d) Rectangular

One of the following statement which is true for relative dielectric constant is -

a) It is dimensionless

b) It is not equal to unity for vacuum

c)) It’s value for all substances is less than one

d)) None

Pure metals generally have-

a) high conductivity and low temperature coefficient

b) high conductivity and large temperature coefficient

c) low conductivity and zero temperature coefficient

d) low conductivity and high temperature coefficient

For small size, high frequency coils, the most common core material is

a) Air

b) Ferrite

c) Powdered ion

d) Steel

For an abrupt junction Varactor diode, the dependence of device capacitance (C) on applied reverse bias (V) is given by-

a) C a V1/3

b) C a V-1/3

c) C a V1/2

d) C a V-1/2

A superconductor is a-

a) A material showing perfect conductivity and Meissner effect below a critical temperature

b) A conductor having zero resistance

c) A perfect conductor with highest dimagnetic susceptibility

d) A perfect conductor which becomes resistive when the current density through it exceeds a critical value

When a semiconductor based temperature transducer has a temperature coefficient of –2500 mV/0C then this transducer is indeed a-

a) Thermistor

b) Forward biased pn junction diode

c) Reverse biased pn junction diode

d) FET

The location of lightning arrestor is -

a) Near the transformer

b) Near the circuit breaker

c) Away from the transformer

d) None

Time constant of an RC circuit increases if the value of the resistance is -

a) Increased

b) Decreased

c) Neither a nor b

d) Both a and b

Intrinsic semiconductors are those which -

a) Are available locally

b) Are made of the semiconductor material in its purest from

c) Have more electrons than holes

d) Have zero energy gaps

The primary control on drain current in a JFET is exerted by -

a) Channel resistance

b) Size of depletion regions

c) Voltage drop across channel

d) Gate reverse bias

The electrical conductivity of metals which is expressed in ohm-1 m-1 is of the order of -

a) 1010

b) 105

c) 10-4

d) 10-6

When biased correctly, a zener diode –

a) acts as a fixed resistance

b) has a constant voltage across it

c) has a constant current passing through it

d) never overheats

The current amplification factor adc is given by –

a) IC/IE

b) IC/IB

c) IB/IC

d) IB/IC

Compared to bipolars, FETs have-

a) high input impedance

b) low input impedance

c) same input impedance

d) none

The source-drain channel of JFET is -

a) ohmic

b) bilateral

c) unilateral

d) both a and b

A diac is equivalent to a -

a) Pair of SCRs

b) Pair of four layer SCRs

c) Diode and two resistors

d) Triac width

When a sample of N type semiconductor has electron density of 6.25 ´ 1011 /cm3 at 300K and if the intrinsic concentration of carriers in this sample is 2.5 ´ 1013/cm3 then the hole density will be –

a) 106/cm3

b) 103/ cm3

c) 1010/ cm3

d) 1012/ cm3

When the two networks shown in fig. are equivalent with respect to the terminals 1 and 2 at all frequencies then the values of CA, LB, LC and CC will be –

a) 0.5, 0.33, 6, 0.166

b) 0.5, 3, 6, 0.66

c) 0.5, 3, 3, 2

d) 0.5, 3, 6, 0.166

The transmission parameter of the network C when the transmission parameter of the network A and B are and respectively are -

The statement ,In any network of linear impedances, the current flowing at any point is equal to the algebraic sum of the currents caused to flow at that point by each of the sources of emf taken separately with all other emf,s reduced to zero’ represents -

a) Kirchhoff,s law

b) Norton,s theorem

c) Thevenin,s theorem

d) Superposition theorem

One of the following modes which has the characteristics of attenuation becoming less as the frequency is increased and is attractive at icrowave frequencies of circular cylindrical wave guides is –

a) TE1 mode

b) TM01 mode

c) TE01 mode

d) Higher order mode

A two-port network is symmetrical if –

a) z11z22 – z12z21 = 1

b) h11h22 – h12h21 = 1

c) AD – BC = 1

d) y11y22 – y12y21 = 1

For transmission line load matching over a range of frequencies, it is best to use a-

a) balun

b) broad band directional coupler

c) double stub

d) single stub of adjustable position

The poles and zeros of a driving point function of a network are simple and interlace on the negative real axis with a pole closest to the origin. It can be realised -

a) by an LC network

b) as an RC driving point impedance

c) as an RC driving point admittance

d) only by an RLC network

Poles and zeros of a driving point function of a network are simple and interlace on the jw axis. The network consists of elements –

a) R and C

b) L and C

c) R and L

d) R, L and C

For a two port reciprocal network, the output open circuit voltage divided by the input current is equal to –

a) B

b) Z12

d) h12

In a short electric doublet the radiation properties are so that-

a) The induction field diminishes as the square root of the distance and is only appreciable in the vicinity of the conductor.

b) In the radiation, magnetic field is minimum when the current is maximum.

c) The radiation resistance of a short doublet antenna is extremely high.

d) Mean rate of power through a unit area of spherical sphere surrounding this doublet is proportional to the square of the elemental length, other factors remaining constant.

The frequency modulated (FM) radio frequency range is nearly -

a) 250 –300 MHz

b) 150 – 200 MHz

c) 90 – 105 MHz

d) 30-70 MHz

In an underground cable the distortion in the transmission of carrier frequency can be eliminated by using -

a) Inductive loading

b) Resistive loading

c) Capacitive loading

d) Shielding

The charachteristic impendance of a transmission line with inductance 0.294 mH /m and capacitance 60 pF/m is -

a) 49 W

b) 60 W

c) 70 W

d) 140 W

One of the following statements which is not true for a strip line compared to a waveguide is –

a) It can be directly connected to semiconductor microwave devices

b) It is much smaller in size

c) It has a smaller bandwidth

d) Losses are less

For a quarter wavelength ideal transmission line of characteristic impedance 50 ohms and load impedance 100 ohms, the input impedance will be –

a) 25W

b) 50W

c) 100W

d) 150W

The depth of penetration or skin depth for an electromagnetic field of frequency ‘f’ in a conductor of resistivity r and permeability m is-

a) inversely proportional to r and f and directly proportional to m

b) directly proportional to r and inversely proportional to f and m

c) directly proportional to f and inversely proportional to r and m

d) inversely proportional to r and m and directly proportional to f

When an antenna has a gain of 44dB then assuming that the main beam of the antenna is circular in cross-section the beam width will be -

a) 0.4456 0

b) 1.44560

c) 2.44560

d) 3.44560

Lens antennas used for microwaves are usually made of -

a) Polystyrene

b) Glass of low refractive index

c) Paraboloid surfaces

d) Dielectric media having large refractive index

One of the following types of instrument which is an electrometer is -

a) Electrodynamometer

b) PMMC

c) Electrostatic

d) Moving iron

When an ac current of 5A and dc current of 5A flow simultaneously through a circuit then which of the following statement is true ?

a) An ac ammeter will read less than 10A but more than 5A

b) An ac ammeter will read only 5A

c) A dc ammeter will read 10A

d) A dc ammeter will read zero

When Q factor of a circuit is high, then -

a) power factor of the circuit is high

b) impedance of the circuit is high

c) bandwidth is large

d) none of these

The resolution of a logic analyser is -

a) the maximum number of input channels

b) the minimum duration of the glitch it can capture

c) it,s internal clock period

d) the minimum amplitude of input signal it can display

The aperture time of an A to D converter is given by -

A memoryless system is –

a) causal

b) not causal

c) nothing can be said

d) none

An air capacitor is a –

a) time variant

b) active device

c) time invariant

d) time invariant and passive device

Thermistors are made of -

a) pure metals

b) pure insulators

c) sintered mixtures of metallic oxides

d) pure semiconductor

Pirani gauge is used to measure –

a) very low pressures

b) high pressures

c) pressures in the region of 1 atm

d) fluid flow

These circuits converts input power at one frequency to output power at a different frequency through one stage conversion –

a) AC voltage controllers

b) Cyclo converters

c) Phase controlled rectifiers

d) Inverters

In a forward voltage Triggering thyristor changes from –

a) off state to on state

b) on state to off state

c) on state to on state

d) off state to off state

Q factor of a coil in Maxwell bridge is obtained as –

A thyristor, when triggered, will change from forward blocking state to conduction state if its anode to cathode voltage is equal to -

a) peak repetitive off state forward voltage

b) peak working off state forward voltage

c) peak working off state reverse voltage

d) peak non-repetitive off state forward voltage

Gate characteristic of a thyristor-

a) is a straight line passing through origin

b) is of the type Vg = a + bIg

c) is a curve between Vg and Ig

d) has a spread between two curves of Vg – Ig

A four quadrant operation requires-

a) two full converters in series

b) two full converters connected back to back

c) two full converters connected in parallel

d) two semi converters connected back to back

If for a single phase half bridge inverter, the amplitude of output voltage is Vs and the output power is P, then their corresponding values for a single phase full bridge inverter are –

a) Vs, P

b) Vs/2, P

c) 2Vs, 2P

d) 2Vs, P

For critical damping of the resonant circuit consisting of Rd, L, C in series is –

d) none of the above

In an enhancement type MOSFET the output V-I characteristics has –

a) only an ohmic region

b) only a saturation region

c) only ohmic region at 10 W voltage value followed by a saturation region at higher voltages

d)an ohmic region at large voltage values preceded by a saturation region at lower voltages

The energy gap in a semiconductor -

a) increases with temperature

b) remains constant

c) slightly increase with temperature

d) decrease with temperature

In an electronic circuit matching means -

a) connecting a high impedance directly to low impedance

b) selection of components which are compatible

c) transferring maximum amount of signal between different kinds of circuits.

d) RC coupled stages

P channel FETs are less superior than N channel FETs because

a) They have higher input impedance

b) They have high switching time

c) They consume less power

d) Mobility of electrons is greater than that of holes

Small increase in temperature in the CE connected transistor is the -

a) Increase in ICEO

b) Increase in ac current gain

c) Decrease in ac current gain

d) Increase in output resistance

An amplifier has a band width of 20 KHz and a midband gain of 50 without feedback. If a negative feedback of 1% is applied then bandwidth with feedback is -

a) 13. 3 KHz

b) 30KHz

c) 10KHz

d) 40KHz

The output of a class B amplifier -

a) is distortion free

b) consists of positive half cycles only

c) is like the output of a full wave rectifier

d) comprises short duration current pulses

An amplifier with negative feedback -

a) lowers its lower 3 dB frequency

b) raises its upper 3 dB frequency

c) increases its bandwidth

d) all of the above

What changes would be necessary in block C if FM signals are to be received -

a) Block becomes redundant

b) A FM detector would be required

c) A high frequency signal generator

d) An additional local oscillator will be needed

The main disadvantage of Diode-Transistor logic (DTL) is its-

a) greater speed

b) slower speed

c) average speed

d) none of the above

Time delay Dt in digital signals in an SIS O shift register is given by –

a) Dt = N ´ Fc

b) Dt = N ´ 1/Fc

c) Dt = 1/N ´ Fc

d) Dt = N ¸ 1/Fc

The output Qn is 1 in a JK flip flop and it does not change when clock pulse is applied) The possible combination of Jn and Kn can be –

(y denotes don,t care)

a) y and 0

b) y and 1

c) 0 and y

d) 1 and y

Basic memory cell of dynamic RAM consists of –

a) a flip flop

b) a transistor acting as a capacitor

c) a transistor

d) a capacitance

The 2,s complement of 10002 is –

a) 0111

b) 0101

c) 1000

d) 0001

Master slave flip-flop is made up of –

a) two flip flops connected in series

b) two flip flops connected in parallel

c) a debouncer circuit

d) a-D- latch

Number of nybbles making one byte is –

a) 2

b) 4

c) 8

d) 16

The intrinsic impedance of free space-

a) is independent of frequency

b) decreases with increase of frequency

c) increases with increase of frequency

d) varies as square root of frequency

A system consists of 12 poles and 2 zeroes. Its high frequency asymptote in its magnitude plot has a slope of -

a) –200 dB/decade

b) –240 dB/decade

c) –230 dB/decade

d) –320 dB/decade

In a unity feed back control system the open loop transfer function is

The closed loop transfer unit will have pole at –

a) –2, -2

b) –2, -1

c) –2, +j1,-j1

d) –2, 2

In a compensating network the transfer function is of the form If this is a phase log network the value of should be –

a) exactly equal to 0

b) between 0 and 1

c) exactly equal to 1

d) greater than 1

Considering the conditions-

1. High loop gain 2. Less ringing

3. Greater damping 4 Negative dB gain margin

System stability requirements would include

a) 1 and 3

b) 1, 2 and 3

c) 1 and 4

d) 2, 3 and 4

A typical control system is shown.

Assuming the steady state errors is given by

The centre and radius of M of circles are given respectively by

The open –loop transfer function for a unity feedback system is –

what is the steady state error if the input is,

r(t) = (2 + 3t + 4t2) u(t)

a) 0

b) 1

c) 2

d) 3

The sensitivity SGM of a system with the transfer function is given by

In the equatorial plane only Geosychronous satellite are launched because it is the only plane which provides –

a) 24 hour orbit

b) stationary satellite

c) global communication

d) zero-gravity environs

Radio Broadcasting is an example of –

a) space multiplexing

b) time multiplexing

c) frequency multiplexing

d) none of the above

PAM signals can be demodulation by using a –

a) Low pass filters (LPE) alone

b) A Schmitt trigger followed by a LPF

c) A differentiator followed by a LPF

d) A clipper circuit by a LPF

In an FDM receiver channels can be separated by using –

a) AND gates

b) Band pass

c) differentiation

d) Integration

The most common modulation system used for telegraphy is-

a) frequency shift keying

b) two – tone modulation

c) pulse code modulation

d) single tone modulation

Use of varoctor diode in generation of modulated segial be-

a) FM generation only

b) 100AM generation only

c) PM generation only

d) both PM and AM generation

In colour picture tube shadow mask is used to-

a) reduce x-ray emission

b) ensure that each beam strikes only its own dots

c) increase screen brightness

d) provide degaussing for the screen

The circuit that separates composite video warefore from the sync pulses is-

a) the keyed AGC amplifar

b) a clipper

c) an integrator

d) a sawtooth current

Band width of microwaves is-

a) 1GHz -103 GHz

b) 1GHz –100 GHz

c) 1 GHz –10 GHz

d) 1 GHz – 106 GHz

In transverse Magnetic mode-

a) no electric line is in direction of propagation

b) no magnetic line is in direction of propagation

c) bath magnetic & electric lines are is direction of propagation

d) neither magnetic nor electric lines in direction of propagation

Signal transmission in sky wave propagation is due to –

a) Reforction of wave

b) Reflection of wave

c) Pierus through Inosphere

d) None

According to Barkhausen Criterion Phase shift of signal should be –

a) 600

b) 900

c) 1800

d) 3600

The transmission does not have -

a) Partition noise

b) Flicker noise

c) resistance

d) Short noise

Varoctor diode has non linearity of -

a) capacitance

b) Inductance

c) Resistance

d) Is a linear device

Scattering matrix equation for directional coupler is –

a)

b)

c)

d)

Noise figure is calculated as –

a) i/p signal to noise ratio X o/p signal to noise ratio

b) i/p S/N Ratio / O/P S/N Ratio

c) i/p S/N Ratio / O/P S/N Ratio X 100

d) i/p S/N Ratio + O/P S/N Ratio

You can determine quickly the effect of adding poles and zeros by –

a) Nicholas chart

b) Nyquist plot

c) Bode plot

d) Root locus.

The polar plot of G(S) = intercepts real axis at w = wo. Then, the real part and wo are given by-

a) –5, 1

b) –2.5, 1

c) –5,0-5

d) –5, 2

Laplace transform F (s) of a function f (E) is given by

The initial and final values of F (t) will be respectively-

a) zero and 1

b) zero and 10

c) 10 and zero

d) 70 and 80

A satellite link uses different frequencies for receiving and transmitting in order to –

a) avoid interference from terrestrial microwave links

b) avoid interference between its powerful transmitted signals and weak in coming signal

c) minimize free-space losses

d) maximize antenna gain

The first determining factor in selecting a satellite system is its-

a) EIRP

b) Antenna size

c) Coverage area

d) Antenna gain

Equalizing pulses in TV are sent during-

a) horizontal blanking

b) vertical blanking

c) the serrations

d) the horizontal retrace

The son seems to have -------- from his father a somewhat gloomy and moody manner-

a) washed

b) inherited

c) admired

d) attempt

Essayist works with words as sculptor with-

a) water

b) stone

c) air

d) hills

What is a collection of sheep called ?

a) bunch

b) flock

c) herd

d) comet

Join these sentences meaningfully by choosing the correct alternative from the following :

You can buy a book. You can read it.

a) and

b) nor

c) either

d) neither

What is the opposite of Asperity –

a) gentility

b) superiority

c) kindness

d) clarity

The Election Commission functions under-

a) Ministry of Home Affairs

b) Ministry of Law

c) Prime Minister,s Secretariat

d) None of these

Article 352 of Indian Constitution needs to be revoked in case-

a) President,s Rule is to be imposed

b) Emergency is declared

c) Services of a Government servant are to be terminated without any enquiry

d) A political party of national level is to be banned

Radio-activity was first discovered by-

a) Becquerel

b) Madam Curie

c) Rutherford

d) Jenner

Ninth Plan in India ranges from-

a) 1995-2000

b) 1996-2001

c) 1997-2002

d) 1998-2003

How much electricity does India propose to generate through nuclear power by the year 2000 AD?

a) 5,000 MW

b) 10,000 MW

c) 15,000 MW

d) 20,000 MW

In which year did the fall of Bastille take place?

a) 1769

b) 1789

c) 1889

d) 1869

To form a quorum how many members of the Lok Sabha or Rajya Sabha should be present?

a) 1/10th of total membership

b) 1/6th of total membership

c) 1/4th of total membership

d) 1/5th of total membership

How may countries are non-permanent members of the Security Council?

a) 6

b) 7

c) 9

d) 10

The International Date Line is represented by-

a) 1000 meridian

b) 00 meridian

c) 1800 meridian

d) 900 meridian

India,s first satellite was launched from-

a) Sriharikota

b) Cape Kennedy

c) Bangalore

d) A Soviet cosmodrome

Name the author of the famous book "Politics"-

a) Aristotle

b) Socrates

c) Plato

d) None of them

"Guernica" is Picasso,s painting on-

a) The Spanish Civil War

b) The American Civil War

c) The French Revolution

d) The Russian Revolution

The object of the Supreme Court,s Keshvanand Bharati ruling is -

a) To put a limit on Parliament,s amendatory powers

b) To give unlimited powers to Parliament to amend the Constitution

c) To give precedence to Directive Principles over Fundamental Rights

d) None of these

Which country in July ,99 officially announced mastering of indigenously developed neutron bomb technology?

a) N. Korea

b) France

c) India

d) China

Shifting cultivation is commonly used in which of the following states?

a) Tamil Nadu

b) Maharashtra

c) Jammu and Kashmir

d) Nagaland

BSNL Whole Testpaper Paper - 6

1. Reactive current through the inductive load produces-
2. a) Magnetic field
3. b) Electric field
4. c) Super magnetic field
5. d) None

6. When a piece of copper and another of germanium are cooled from room temperature to 80⁰ K then the resistance of -

   a) each of them increases

   b) each of them decreases

   c) copper increases and germanium decreases

   d) copper decreases and germanium increases

7. A capacitance transducer has two plates of area 5 cm² each separated by an air gap of 2mm. Displacement sensitivity in pF /cm due to gap change would be -

   a) 11.1

   b) 44.2

   c) 52.3

   d) 66.3

8. The critical angle in degrees, for an electromagnetic wave passing from Quartz (m = m_0, Î=4Î_o) into air is-

   a) 15

   b)30

   c)45

   d)90

9. When an RC driving point impedance function has zeros at s= -2 and s=-5 then the admissible poles for the function would be –

   a) s = 0; s = -6

   b) s = -1; s = -3

   c) s = 0; s = -1

   d) s = -3; s = -4

10. A capacitor used for power factor correction in single- phase circuit decreases –

    a) the power factor

    b) the line current

    c) Both the line current and the power factor

    d) the line current and increases power factor

11. The unit of inductance is –

    a) ohm

    b) inductive reactance

    c) inducta

    d) Henry

12. Which type of by-pass capacitor works best at high frequencies –

    a) electrolytic

    b) mica

    c) ceramic

    d) plexiglass

13. The usual value of the surge impedance of a telephone line is –

    a) 600 W

    b) 500 W

    c) 75 W

    d) none

14. Telemetering is a method of –

    a) counting pulses, sent over long distances

    b) transmitting pictures from one place to another

    c) transmitting information concerning a process over a distance

    d) None

15. In an unbiased P-N junction thickness of depletion layer is of the order of –

    a) 0.005 mm

    b) 0.5 mm

    c) 5 mm

    d) 10^-10 m

16. One of the semiconductor device, which behaves like two SCRs is–

    a) UJT

    b) triac

    c) JFET

    d) MOSFET

17. The following, which is not an advantage of semiconductor strain gauges as compared to conventional strain gauges, is –

    a) excellent hysterists characteristics

    b) least sensitive to temperature changes

    c) high fatigue life

    d) smaller size

18. The fundamental ripple frequency of a half wave 3F rectifier with a 3F supply of frequency 50 Hz is –

    a) 150 Hz

    b) 50 Hz

    c) 100 Hz

    d) 250 Hz.

19. For an FR biased PNP transistor –

    a) base is negative with respect to emitter

    b) collector is positive with respect to emitter

    c) collector is a little more positive than base

    d) base is a little less positive with respect to emitter than collector

20. With normal operation of a JFET one can get I_Dss –

    a) the maximum drain current

    b) the minimum drain current

    c) normal drain current

    d) none

21. An SCR is a semiconductor device made up of –

    a) Four N type layers

    b) Two P types and three N type layers

    c) Two P type and two N type layers

    d) Three P type and one N type layers

22. For a UJT, if R₁ = resistance from emitter to base 1, R₂ = resistance from emitter to the base 2 and R_BB = R₁ + R₂ then the intrinsic stand off ratio (h) is –

    a)

    b)

    c)

    d)

23. As the drain voltage is increased for a junction FET in the pinch off region then the drain current –

    a) becomes zero

    b) abruptly decreases

    c) abruptly increases

    d) remains constant

24. 20 When the energy gap of a semiconductor is 1.1eV then it would be –

    a) opaque to the visible light

    b) transparent to the visible light

    c) transparent to the infrared radiation

    d) opaque to the infrared radiation

25. The equivalent capacitance across ab will be –

    

    

    

    

    d) 0

26. In the following fig. the power dissipated is maximum when the value of R_x is –

    

    a) 33.4 K

    b) 17.6 K

    c) 10 K

    d) 5 K

27. The transfer function of a low pass RC network is –

    

    

    

    
    

28. The total capacitance across points ,a, and ,b, in the given figure is –

    

    a) 1.66 mF

    b) 2.66 mF

    c) 3.5 mF

    d) 4.5 mF

29. The load resistance needed to extract maximum power from the following circuit is –

    

    a) 2W

    b) 9W

    c) 6W

    d) 18W

30. Which one of the following conditions for z parameters would hold for a two port network containing linear bilateral passive circuit elements –

    a) z₁₁ = z₂₂

    b) z₁₂z₂₁ = z₁₁z₂₂

    c) z₁₁z₁₂ = z₂₂z₂₁

    d) z₁₂ = z₂₁

31. In the network shown, the switch is opened at t = 0. Prior to that, the network was in the steady state, Vs(t) at t = 0 is –

    

    a) 0

    b) 5V

    c) 10V

    d) 15V

32. Which of the following statements are correct –

    1. Tellegen,s theorem is applicable to any lumped network

    2. The reciprocity theorem is applicable to linear bilateral networks.

    3. Thevenin,s theorem is applicable to two terminal linear active networks.

    4. Norton,s theorem is applicable to two terminal linear active networks.

    a) 1, 2 and 3

    b) 1, 2, 3 and 4

    c) 1, 2 and 4

    d) 3 and 4

33. Which one of the following transfer functions represents the critically damped system ?

    

    

    

    

34. When the respective coil impedance of the circuit shown in the fig. is are Z₁ = (5 + j8)W and Z₂=(3+j8) then the input impedance of the circuit will be –

    

    a) (8 + 16j)W

    b) (2 + j0)W

    c) (15 + 64j)W

    d) (8 + 0j)W

35. One of the following statement which is not correct -

    a) In case of an antenna, the radiation resistance and loss resistance are not two different quantities.

    b) The loss resistance includes loss by eddy currents, improper earth connections, insulation leakages etc) but not I²R losses

    c) Radiation resistance varies directly as square root of the frequency

    d) None of the above

36. Ultraviolet radiation emitted when electron jumps from an outer stationary orbit to -.

    a) first stationary orbit

    b) second stationary orbit

    c) third stationary orbit

    d) fourth stationary orbit

37. When the signal is propogated in a waveguide which has a full wave of electric intensity change between the two farther walls and no component of the electric field in the direction of propogation then the mode is –

    a) TE₁₁

    b) TE₁₀

    c) TM₂₂

    d) TE₂₀

38. Consider the following statements pertaining to parabolic antenna -

    1.It is commonly used above 1GHz

    2. It get’s circularly polarized

    3. It’s radiation pattern is highly directional

    4. It’s radiation pattern is cardiod

    of these statements-

    a) 1,2 and 4 are correct

    b) 1 and 3 are correct

    c) 1,2 and 3 are correct

    d) 2 and 4 are correct

39. When a vertical dipole antenna is used in conjunction with a loop antenna for direction finding, then the field pattern obtained will be-

    

    

    

    

40. When one end of a loss less transmission line of length 3/8 l and characteristic impedance R₀ is short circuited and the other end is terminated in Ro then the impedance at l/8 away from the end terminated in R₀ is-

    a) Zero

    b) R₀

    c) R₀/2

    d) Infinite

41. For transmission of wave from a dielectric permittivity Î₁ into dielectric medium of lower permittivity Î₂ (Î₁ > Î₂) the critical angle of incidence Qc ( relative to the interface ) is given by -

    

    

    

    

42. A transmission line has primary constants R, L, G and C and secondary constants Z₀ and g (= a + jb) if the line is loss less then .

    

    

    

    

43. The intrinsic impedance of a free space is-

    

    

    

    

44. One of the following which is a low gain but omni directional antenna is-

    a) discone

    b) log-periodic

    c) loop

    d) helical

45. Electronic voltmeters have –

    a) high input impedance

    b) low input impedance

    c) zero input impedance

    d) none

46. Which of the following statement about impulse voltage is true ?

    a) An impulse voltage is an unidirectional voltage.

    b) In chopped impulse voltage, flashover does not occur.

    c) Time taken to rise is exactly equal to the time taken to fall.

    d) RMS value of impulse voltage is always less than 50% of average value.

47. The precision of an instrument indicates its ability to reproduce a certain reading with a given –

    a) drift

    b) resolution

    c) shift.

    d) consistency

48. In heterodyne digital conductor, the input signal is heterodyned to a –

    a) higher frequency

    b) lower frequency

    c) both a and b)

    d) none

49. In a digital measuring device, if the input electrical signal is in the frequency range dc to f_max Hz, then it must be sampled at a rate of –

    a) f_max times/sec

    b) f_max times/ses

    c) every 2f_max/sec

    d) 2 f_max times/sec .

50. Moving Iron intruments measures the rms value of –

    a) a direct quantity

    b) an alternating quantity

    c) a virtual quantity.

    d) none.

51. One of the following intruments which is used almost exclusively to measure radio frequency current is-

    a) Moving coil meter

    b) Rectifier-type moving coil meter

    c) Iron-vane meter

    d) Thermocouple meter.

52. A good ohmic contact on a p- type semiconductor chip is formed by introducing –

    a) gold as an impurity below the contact

    b) a high concentration of donors below the contract

    c) a high concentration of acceptors below the contact

    d) a thin insulator layer between the metal and semiconductor.

53. The use of thermocouple meters for ac measurement leads to a meterscale which is –

    a) linear

    b) square law

    c) logarithmic

    d) exponential

54. If low pressure of the order of 10^-6mm of Hg is to be measure then the instrument of choice would be-

    a) compound pressure gauge

    b) thermocouple vacuum gauge

    c) pirani gauge

    d) ionization type vacuum gauge

55. 

    In the given circuit if the power dissipated in the 6W resister is zero then V is –

    a)

    b)

    c)

    d)