ExamNotice

BSNL GE-JTO Recruitment Examination

Test Paper - X

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

The main purpose of plating the high frequency inductors and capacitors with silver is to

a.) Reduce their dc resistances

b.) Reduce their ac resistances

c. )Increase their ac resistance

d.) Increases their dc resistance

In a semiconductor the measurement of Hall coefficient provides information on the –

a. )Sign and mass of charge carriers

b.) Mass and concentration of charge carriers

c.) Sign of charge carries alone

d. )Sign and concentration of charge carriers

In electrical machines, laminated cores are used with a view to reduce –

a.) Hysteresis loss

b.) Eddy current loss

c. )Magnetic loss

d.) None

In a cable the voltage stress is maximum at the surface of the –

a.) Sheath

b.) conductor

c.) Insulator

d.) None

The series equivalent resistance value in case of a lossy capacitor will be –

a.) Very small

b.) Small

c.) Large

d.) None

One of the following material which has negative temperature coefficient of resistance is-

a. )Brass

b. )Copper

c. )Aluminium

d.) Carbon

The input impedance of a CRD is nearly –

a. )zero

b.) around 10 ohms

c. )around 100 ohms

d.) around one mega ohm

9. In order to convert intrinsic semiconductors into extrinsic ones, the level of doping required is about –

a.) 1 : 103

b.) 1 : 1

c.) 1 : 108

d. )1 : 105

One of the following, which is not a transducer in the true sense, is –

a. )Thermocouple

b.) Piezoelectric pick up

c. )Photo-Voltaic cell

d. )LCD

The threshold voltage of a MOSFET can be lowered by –

a. )Using a thinner gate oxide

b. )Increasing the substrate concentration

c. )Both a & b

d.) None

The resistance of a metallic wire would –

a.) Increase as the operating frequency increases.

b.) Decrease as the operating frequency increases

c.) Remain unaffected on increasing the operating frequency

d.) None

One of the following statements which is correct regarding the two transistor model of the p-n-p-n four layer device is –

a. )It explains only the turn ON portion of the device characteristic.

b. )It explains only the turn OFF portion of the device characteristics.

c.) It explains only the negative region portion of the device characteristics.

d. )It explains all the regions of the device characteristics.

The gain-band width product of a junction transistor is affected to a maximum extent by –

a.) Base collector parasitic capacitance

b.) Base collector space charge layer capacitance

c.) Base collector space charge layer capacitance

d. )Base emitter diffusion capacitance

The modulation of effective base width by collector voltage is known as early effect, hence reverse collector voltage –

a.) Increases both alpha and beta

b.) Decreases both alpha and beta

c.) Increases alpha but decreases beta

d.) Decreases beta but increase alpha.

One of the following theorem which is the manifestation of the law of conservation of energy is –

a. )Tellegen's theorem

b.) Reciprocity theorem

c. )Thevenin's theorem

d. )Norton's theorem

The network shown in the fig. represents a :

a.) band-pass filter

b) low-pass filter

c.) high-pass filter

d.) band-stop filter

For the circuit shown in the fig. the current I is –

a.) indeterminable due to inadequate data

b) zero

c.) 4A

d.) 8A

1When the p network of figure – I and T-network of figure – II are equivalent then the values of R1, R2 and R3 will be respectively –

a.) 9W, 6W and 6W

b) 6W, 6W and 9W

c.) 9W, 6W and 9W

d.) 6W, 9W and 6W

When two identical 3v, 1W batteries are connected in parallel with like polarity to like then the Norton equivalent circuit of this combination is –

a) 3A, 0.5W

b.) 6A, 1W

c.) 3A, 1W

d.) 6A, 0.5W

The dominate mode in a waveguide is characterized by-

a.)Longest cut off wavelength

b.) Shortest cut off wavelength

c.) Infinite attenuation

d.) Zero attenuation

22. The antenna most commonly used for TV broadcasting in the UHF band is

a.) Turnstile antenna

b.) Dipole antenna

c. ) Yagi antenna

d.)Rhombic antenna

The crossed dipoles in turnstile antenna are excited with voltage such that the phase shift between the voltage is-

a.) Zero

b.) 450

c.) 900

d.) 1800

The channel required for FM telemetry is-

a.) The same as that required for AM telemetry

b.) Smaller than the required for AM telemetry

c. ) 100 Times that required for AM telemetry

d. )10 times that required for AM telemetry

When the input impedance of loss-less transmission line is 100 ohms when terminated in a short circuit and 64 ohms when terminated in an open circuit, then the input impedance of the line is

a. ) 80 W

b. )164 W

c.) 36 W

Evanescent mode attenuation in a waveguide depends upon the-

a.) 32 GHz

b.) 8 GHz

Out of the following the one that mostly reflects the high frequency radio waves is-

a.) D

b). E

c.) F1

d.) F2

One of the following which is not a wide band antenna is-

a.) Marconi

b.) Helical

c.) Rhombic

d. )Folded dipole

The power carried by an electromagnetic wave traveling in free space changes with distance ‘d’ in proportion to-

a.) d

b.) 1/d

c.) 1/d2

d.) d2

In a FM receiver, the channel bandwidth is around-

a.) 10 KHz

b.) 20 KHz

c.) 75 KHz

d.) 200 KHz

When the power of transmitter is doubled, then the field strength at a point will go up by-

a.) 2 dB

b.) 6 dB

c.) 3 dB

d.) None

In any transmitting antenna system, efficiency primarily depends upon-

a.) Ohmic losses of various conductors

b.) Radiation resistance

c.) Ground conductivity

d.) Atmospheric conditions

The signal to quantisation noise ratio in a PCM system depends upon –

a.) sampling rate

b.) number of quantisation levels

c.) massage signal band width

d.) size of the transmission system.

Q. is –

a.) directly proportional to damping factor.

b.) inversely proportional to damping factor.

c.) directly proportional to the square of damping factor.

d.) directly proportional to the cube of damping factor.

A dry cell is a –

a.) time variant only

b.) active device only

c.) time-varying and active device

d. )none.

A digital frequency counter can be converted to a DVM by addition of a stage of suitable –

a.) voltage controlled oscillator

b.) D/A converter to it

c.)power amplifier to it

d. )operational amplifier to it.

A 0 to 200 V dc moving coil voltmeter has a guaranteed accuracy of 0.75 % of full scale reading. The voltage measured by instrument is 100V. The limiting error is –

a. )3%

b.) 2%

c. )1.5%

d. )0.75%

. The dynamic characteristics of capacitive transducers are similar to those of a –

a. )low pass filter

b.) high pass filter

c. )notch filter

d. )band stop filter

The temperature coefficient of resistance for a thermistor is –

a.) low and negative

b.) low and positive

c.) high and negative

d. )high and positive

Which of the following types of transducers can be used for measurement of an angular position is –

a. )Circular potentiometer

b.) Synchro

c.) E-pick off

d.) both a and b

A 300V full-scale deflection voltmeter has an accuracy of ± 2 %. When it reads 222V. The actual voltage –

a.) Lies between 217.56V and 226.44V

b.) Lies between 217.4V and 226.6V

c. )Lies between 216V and 228V

d. )Is exactly 222V

In a thyristor, ratio of latching current to holding current is-

a.) 0.4

b.) 1.0

c.) 2.5

d.)6.0

In a single-phase full converter bridge the average output voltage is given by-

a. b.

c. d.

A 3 phase semi converter can work as-

a.) converter for a = 00 to 1800

b.) converter for a = 00 to 900

c.) inverter for a = 900 to 1800

d.) inverter for a = 00 to 900

In the given arrangement A-3 the circuit is initially in steady stale with thyristor T off. At the moment thyristor T is turned on the thyristor current is –

a.) 2 A

b.) 22 A

c.) 40A

d.) 42 A

In dc choppers for chopping period T, the out put voltage can be controlled by FM by varying-

a) T keeping Ton constant

b.) T off keeping T constant

c.) T keeping T off constant

d.) none of the above

In synchronized UJT friggering of an SCR, voltage Vo across capacitor reaches UJT threshhold voltage thrice in each half cycle so that there are three firing pulses during each half cycle. The firing angle of the SCR can be controlled.

a.) once in each half cycle.

b.) thrice in each half cycle

c.) twice in each half cycle.

d. )four times in each half cycle.

When a series LC circuit is connected to a dc supply of V volt through a thyristor, then the peak current through thyristor is-

In a single phase voltage controller with RL load, ac output power can be controlled if

a). firing angle a > and (load phase angle) and conduction angle

b. )

c. )

d. )

Class C amplifier is mainly used as-

a. ) As an RF amplifier

b.) As stereo amplifier

c.) In communication sound equipment

d.) As distortion generator

Parasitic oscillations in amplifiers are caused by-

a. ) Negative feedback

b.) Push-pull operation

c.) Poor interstage coupling

d.) Transistor inter – junction capacitance

The input impedance in a voltage shunt feedback is-

a.) decreased

b.) Increased

c.) Remains unchanged

d. )None of the above

The signal/noise (S/N) ratio of an amplifier developing an output voltage of 10 v and a noise voltage of 1 mV is ------ dB

a.)40

b.)100

c.)-40

d.)80

The feedback factor ‘BAv’ is negative for negative feedback-

a.) True

b). False

c). May or May not be

d). None of the above

For sustaining oscillations in a feedback amplifier the loop gain should be-

a. ) Zero

b.) Less than one

c.) Greater than one

d.) None of the above

An operational amplifier has a slew rate of 100 v/ microsecond. For a frequency of 10MHz the maximum value of the sine-wave output voltage will be-

a.)100 v

b.)50/p v

c).10v

d).5v

A signal having uniformly distributed amplitude in the interval (-v,+v) is to be encoded using PCM with uniform quantization. The signal to quantizing noise ratio is determined by the-

a. ) Dynamic range of the signal

b.) Number of quantizing level

c.) Sampling rate

d). Power spectrum of signal

For signal amplitude modulated to a depth of 100 % by a sinusoidal signal power is-

a. ) Same as the power of unmodulated carrier

b.) Twice as the power of unmodulated carrier

c. ) 3/2 times the power of unmodulated carrier

d.) 2/3 times the power of unmodulated carrier

Identify the false statement about MOSFET.

It can deplete in-

a.) Depletion mode

b). Enhancement modes

c.) Depletion and enhancement modes

d. )Depletion only mode

The process of conversion from an analog signal to digital signal is known as an –

a.) analog to digital conversion

b.) digital to analog conversion

c.) analog to analog conversion

d.) digital to digital conversion

TTL circuits are used in main frame computers because of their –

a.) fast operating speed

b.) slow operating speed

c.) medium operating speed

d.) none of the above

When a large number of analog signals is to be converted to digital form, an analog multiplexor is used. The A to D converter suitable in this case will be –

a.) dual slope type

b.) up down counter type

c.) successive approximation type

d.) forward counter type

Identity wrong rule for binary subtraction ?

a.) 0 – 0 = 0

b.) 1 – 0 = 1

c.) 1 – 1 = 0

d. )0 – 1 = -1 with borrow of 1

The binary equivalent of 9.37510 is –

a.) 1001.0112

b.) 1101.1012

c.) 1100.0112

d.) 1111.0012

In FM if transmission bandwidth is doubled then the SNR is-

a.) Also doubled

b) Improved fourfold

c.) Decreased by one fourth

d.) Unaffected

Main memory are of two kinds –

a.) ROM and RAM

b.) random and sequential

c.) primary and secondary

d.) central and peripheral

The resolution for n bit system D/A converter is –

In a PCM system, the number of quantization level are 16 and the maximum signal frequency is 4KHz. The bit transmission rate is-

a.) 64 K bits / sec

b.) 32 bits / sec

c.) 32 K bits /sec

d) 16K bits /sec

Mark out sop in the following-

The reverse saturation Current ICO in a transistor amplifier-

a. )doubles for every 100C rise in temperature

b.) doubles for every 50C rise in temperature

c.) doubles for every 10C rise in temperature

d.) increases linearly with temperature

The given circuit is equivalent to –

a.) b.)

c.) d.)

The interface chip used for data transmission between 8086 and a 16-bit ADC is –

a.) 8529

b.) 8251

c.) 8255

d.) 8253

The output signal amplitudes for1's and 0's in an ADM transmission system –

a) Fixed and the repetition rate is also fixed

b. )Fixed but the repetition rate is variable

c.)Variable and the repetition rate is also variable

d.) variable but the repetition rate is fixed

A composite voltage V = 10 sin 100t + 10cos 100t is applied across a series combination of a capacitor of 1/mF and a resistance of 10 kW. The average power dissipated in the resistance is –

a.) 5mW

b.) 3.5mW

c. )4mW

d.) 8mW

Considering a negative feedback system

The closed loop system is stable for

Mark the features of the break away point in the root locus of a closed loop control system with the characteristic equation 1+ KG1 (s) H1 (s) = 0

1. It need not always occur only on the real axis.

2. At this point G1(s) H1(s) = 0

3. At this point

Select the correct answer using codes below.

a.)1, 2 and 3

b.) 1 and 2

c.) 2 and 3

d.) 1 and 3

Which of the following components can be used as a rotating amplifier in a control system?

1. An amplidyne

2. A separatively excited dc generator

3. A self excited dc generator

4. A sychro

select the correct answer using codes below-

a. )3 and 4

b.) 1 and 2

c). 1, 2 and 3

d.) 1, 2, 3 and 4

In the formation of Routh’s array the situation of a row of zeros indicates that the system-

a.) has symmetrically located roots.

b. )is not sensitive to variations in gain

c.) is stable

d.) unstable

A 3-port circulator is shown in the figure.

Which one of the following scattering matrices related to this circulator?

In the given figure a signal flow graph is shown. Consider the statements regarding the signal flow graph-

1. There are three forward paths

2. There are three individual loops

3. There are two non touching loops

of these statements-

a.) 1, 2 and 3 are correct

b.) 1 and 2 are correct

c.)2 and 3 are correct

d.) 1 and 3 are correct

Mark out wrong statement.

Modulation is used to-

a. )Reduce the bandwidth used

b). Separate differing transmissions

c.) Ensure that intelligence may be transmitted over long distances

d.) Allow the use of practicable antennas

The best scanning system for tracking if the target has been acquired is-

a.) lobe switching

b.) sequential lobbing

c.) conical scanning

d.) monopulse

The amplification in parametric amplifiers used in microwave communication system is limited by-

a.) type of biasing

b.) cassegranian antenna

c.) pyramidal horn antenna

d. )dipole antenna

Gating signal is applied to the circuit as shown in the given figure, to switch the field effect transistor. When gating signal isOV, the output voltage VO will be-

a. )Zero

b.) Sine wave (2Vp-p)

c.) 2Vdc

d.) I/2V

Hamming codes are used for error detection and correction. If the minimum Hamming distance is m, then the number of errors correctable is-

a. )equal to M

b.) less than M/2

c.) equal to 2 M

d.) greater than M

Mark out a wrong statement for two phase servo motor-

a. )The rotor diameter is small

b.) The rotor resistance is low

c. )The applied voltages are seldom balanced

d.) The torque speed characteristic is linear.

The frequency deviation in phase modulation is-

a.) independent of the modulating signal frequency

b.) inversely proportional to the modulating signal frequency

c.) directly proportional to the modulating signal frequency.

d.) inversely proportional to the square root of the modulating frequency.

A telephone channel has bandwidth B of and . It is connected to a Teletype machine having 32 different symbols. The symbols rate required for errorless transmission is nearly-

a. )1800 symbol/s

b.) 3000 symbols/s

c.) 5000 symbols/s

d.) 6000 symbols/s

Which power amplifiers has maximum efficiency?

a.) Class A

b). Class AB

c.) Class B

d.) Class C

Negative resistance characteristics for its operation is used by –

a.) TWT

b). Klystron

c.) Magnetron

d. )MASERS

Is a non mark able interrupt-

a. )RST 7.5

b). RST 6.5

c.) RST 5.5

d.) TRAP

Instructions in C are of type-

a. )2

b. )3

c.) 4

d.) 6

In C programming character variable can at a time store-

a.) 1 character

b.) 8 characters

c.) 16 characters

d.) 256 characters

To obtain 16 x 8 memory using 16x4 memory. How many IC required-

a.) 16

b.) 2

c.) 4

d.) 8

In active low logic, the logic I state corresponds to-

a.) high voltage level

b) low voltage level.

c.) negative voltage

d.) ground level.

If JK inputs are tied together, the circuit reduces to-

a.) SR FF

b.) D FF

c) T FF

d.) JK FF

For designing half adder are require-

a.) a NOT gate and a OR gate

b). a AND gate and a OR gate

c). two AND gate

d.) a AND gate and a X – OR gate

Portly random and portly cyclic sequential access of memory is in-

a.) magnetic tape

b.) CD ROM

c.) Magnetic Drum

d.) Flopy

A pointer which points the memory address of the current or next instruction is-

a.) Index register

b.) Temp register

c.) Program counter

d.) Stack pointer

For address modification purpose computer uses-

a. )Temp register

b.) Index register

c.) Stack pointer

d.) Program counter

Let's go for a walk, . The tag question required for this statement is :

a.) Shall we ?

b.) Should we ?

c.) don't we?

d.) do we ?

He looked very grave

Which of the following words has the closest meaning to the word underlined.

a.) angry

b) serious.

c.) frightened

d.) upset.

Sharma did not work ----- so his master asked him to leave-

a.) proper

b.) properly

c.) rightly

d) straight

Being punctual is necessary in your job. (Substitute the underlined word without changing its meaning) -

a.) attractive

b.) free from worries

c). on time

d.) cheerful

Reema said that she had never ----- a book she liked so much.

a.) held upon

b.) saw into

c.) come across

d.) viewed on

The first bullet train is assembled in –

a. )South Korea

b.) North Korea

c.) Japan

d.) Malaysia

Minister of Parliamentary Affairs and Communications and Information Technology of Government of India is –

a.) Uma Bharati

b.) Pramod Mahajan

c. )Murli Manohar Joshi

d.) Uma Kashyap

Chairman of the Cricket Board’s Zonal Academics is –

a.) N Venkat Rao

b.) Jag Mohan Dalmia

c.) Chandru Borde

d.) Kapil Dev

Romario matched the career total of retired Zico by-

a.) 830 goals

b.) 835 goals

c.) 834 goals

d.) 831 goals

The best source of Vitamin A is

a.) Lime bean

b.) Carrot

c.)Tomato

d. )Orange

Titan is the name of the moon related to planet-

a. )Uranus

b.) Neptune

c. )Saturn

d. )There is no such moon

Word Environment Day was observed on-

a.) 5 May 99

b.) 15 May 99

c.) 5 June 99

d. )5 July 99

Who wrote ‘Mudrarakshasa”?

a. )Kautilya

b.) Visakhadatta

c.) Kalhana

d.) Kalidas

Where were the first Asian Games held?

a.) New Delhi

b). Teheran

c.) Tokyo

d.) Bangkok

Tagore's Gitanjali is-

a. )A collection of poems

b. )A collection of short stories

c. )A collection of dramas

d.) A novel

In which year did Mahatma Gandhi launched it first non cooperation movement-

a. )1917

b.) 1918

c.) 1919

d.) 1920

In how many years is Khumbh Mela held?

a. )3

b). 5

c.) 8

d.) 10

e.) 12

Panchayat polls held in Jammu and Kashmir after the gap of-

a.) 40 years

b.) 20 years

c.) 33 years

d.) 23 years

The hardest part in a tooth is-

a.) Dental tubule

b.) Dentine

c.) Enamel

d.) Pulp

What is 'Pimpri' famous for?

a. )Chemicals factory

b.) Fertilizer factory

c.) Antibiotics factory

d.) Cement factory

e.) None of these.