MODEL TEST PAPER FOR BSNL JTO EXAM




BSNL JTO Model Test Paper

BSNL JTO Model Test Paper --- FOR PRACTICE
1. 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

Ans. a.) Schering bridge

2. LBDT is uses as a –
a) . Displacement transducer
b.) Pressure transducer
c.) Temperature
d.) Any of the above

Ans. a). Displacement transducer

3. 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

Ans. a.) Dielectric constant per unit volume

4. 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

Ans. b.) High frequency response

5. 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.

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

6. 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.) V/I
d.) Delta V/Delta I

Ans. d). Delta V/Delta I

7. 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

Ans. c. )Protect meter movement from stray magnetic fields

8. A capacitor that has been connected across a battery for comparatively long time becomes–
a. ) Charged
b.) Discharged
c.) Short – circuited
d.) Defective

Ans. a. )Charged

9. 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

Ans. c.) Q = CV

10. Silicon steel used for electrical purposes has silicon percentage of –
a. ) 0.5
b.) 2.5
c.) 3.4
d) . None

Ans. c.) 3.4

11. 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

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

12. 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

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

13. A JFET can operate in –
a.) depletion and enhancement model
b. ) depletion mode only
c. ) enhancement mode only
d.) neither enhancement nor depletion mode

Ans. b. )depletion mode only

14. Consider the following semiconductor diodes –
a. ) Germanium diode
b.) Silicon diode
c.) Tunnel diode
d.) Schottky diode

Ans. c.) Tunnel diode

15. 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.

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

16. 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

Ans. c.) CB transfer characteristics

17. 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

Ans. a.) positive with respect to the source

18. The SCR is often employed as a –
a. ) Source-controlled switch
b. ) Drain-controlled switch
c.) Gate-controlled switch
d) None

Ans. c.) Gate-controlled switch

19. 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

Ans.b.) Should be shunted by a 2pF capacitor

20. 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

Ans. c.) Both a and b
21. 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

Ans. a.) I

22. 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

Ans. b.) 0.5 Ohms

23. 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

Ans. a. )1 and 2

24. 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 di(t)/dt at t = 0 will be –



a. )100 amp./sec.

b. )–100 amp./sec.

c. )1000 amp./sec.

d. )–1000 amp./sec.

Ans. b. )–100 amp./sec.

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



a. )6V

b.)10V

c. )25V

d. )40V

Ans. a.)6V

26. 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

Ans. b.) 4V, 4 Ohms

27. 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

Ans. c )R/2

28. 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

Ans. a.)1A

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

30. 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

ip to Not gate gives o/p as-
a ) inversion of some bits

b.) 2's complement of ip

c.) 1's complement of ip

d.) o/p is some as ip

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 < 1/2, y < 1/2

b). x < 0, y < 2

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

d.) x < 0 , y < 1/2

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


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