electrical engineering objective questions part 11

8/9/2019 Electrical Engineering Objective Questions Part 11

1/46

•

c /V09

DO NOT OPEN THIS TEST DOOKLET UNTIL YOU

ARE

ASKED

TODOSO

-

T.B

.C. : P DTQ J FFO

Test Uooklet Series

i l

No.

.

463

TEST BOOKLET

ELECTRICAL ENGINEERING

Sec

Tim

e Alluwed : Two

Hour.

M=imum Marks 30<

INSTRUCTIONS

L

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HAVE

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UNPRINTED OR TORN OR

MISSING

PAGES OR

ITEMS. ETC. IF SO. GET

rr·REPLACED BY

A COMPLETE TEST

BOOKLET.

2.

ENCODE CLEARLY THE TEST BOOKLET SERIES A, B, CORD AS THE CASE MAY

BE IN

THE

APPROPRIATE

PLACE

IN

THE

ANSWER SHEET.

3.

Y(lU have

to

enter your Roll Number on the Test

_Booklet in the Box prov1ded alongside. O

NOT

write anything else on the Test Booklet.

4.

This Test B(l(lklet contains 120 uems (questious). Each item is pronted both in Hindi and English.

Each ilf:m comprises four responses (answers)- You will select the response which you wan

to

mark

on the Answer Sheet. In case you feel ~ h a ~ ~ h e r e is more t b ~ n one correct respome. mark the response

Which you consider the best. In any case, choose ONLY ONE response for eoch item.

You have to mark all ~ o w · responses

ONLY

on the separotc Answer Sheet pres on the Answer Sheet and the examination has

concluded. you should hand over to the lnvigilator

only the Answer Sheet

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away with you the Test Booklet.

Sheets for rough work are appended

in

the Test Booklet at the end.

Penalty for wrong

Answers:

TilERE WILL BE I'ENALTY FOR WRONG ANSWERS MARKED

BY

A CANDIDATE IN THE

OBJECTIVE TYPE QUESTION PAPERS.

(i)

There are four alternatives for the answer

to

every question. For each question for which a

wrong answer has

been

given

by

the candidate,

one-third

(0·33)

of

the

marks assigned to that

que•tion will be deducted as penahy.

{ii)

If a cl i t ~

' "'5

R W T ~ I

.

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2/46

1.

A 2 .iF capacitor

S

charged by con

necting it across a

100

volt DC supply.

The supply

S

then diSCOnnected and

another

J j.lF

uncharged capacitor 1s

connected across this capacitor. If there

S

nO

leakage; which

of

the following

gtves the eorrect voltage across the

plates

of

each

of

the capacitors ?

2.

•

(a)

100

volts

3

b)

100

volts

2

200

volts

3

(d

100 volts

·

•

+

'

-

In the case

of

ahove circuit.· which

one

of

the following statements is -correct ?

(a) It can be analysed by minimurp. one

loop equation

(b)

It

can

be

analysed by

minimum

two

. loop

equations

c) It can be analysed by minimum

three loop equations

(d) It

cannot

be analysed by loop

method

P TQ J FFO A

2

3. A circuit consists

of

several resistors,

on6 independent voltage sourue· and one

i11dependcnt current source only. f the

powers consumed in one

of

lh

0,

then what

are the values of the voltage (in volts)

and charge (in coolomb) on the capacitor

at t=3.

a)

2.

4

b)

4

2

c)

-8,

4

d)

4, g·

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3/46

1. r;


4/46

5.

+

Vs-

H

-:c

Yt:

w

'

'

The network shown in the above figure

is in steady state wirh the switch closed.

At

t '

0 the switch is opened. Which

of

the following gives the voltage across

the switch,

V

and ~ at

t

= o respec

tively

?

(a)

0

and 4

V/s

b) 0 and I V/s

(c) 2 V and 2 V/s

(d) 0 and 2 V/s

6. R, Land Care

connected in series in the

order RLC. f the voltage across R and L

together is 20 V, voltage across L and

together is 9 V and total voltage is

15

V,

then what is the voltage across C?

(a) 7 V

(b)

12 v

(c} 16 V

(d)

21 v

7. In a symmetrical three-phase

~ y s t e m

phase sequence RYB a capacitive

rei:tct

ance 10 ohm is across YB and a coil

R +

jX

across RY. When

ly '

0, which

of

the following gives the values of

Rand X in ohms respectively?

(•)

lO, 0

b)

J0../3, 10

(o)

5J3 5

(d)

s,

s-J3

P DTQ J FFO

- A

4

8:

'o----------


5/46

s.

+ v .-

fH

+.L

-If;;

f

2V·

m{m q & < i ~ 1 'lQT "ll


6/46

10.

What

type

of

system the difference -

equation y n)

=x n) +

x n-

2 - 2

reprc

sems?

(a) Linear time-invariant system

(b) Linear time-varymg system

(c) Non-linear time-invariant s y . ~ t e m

(d) Non-linear time,varying system

11 What is the average value of the

wavefonn x t) =

4

cos

41--'5 sin 5r?

(a) 0

(b)

2

(c)

2

20

(d)

n

12. Which one

of

the following statements

is correct ?

A

discrete

LTJ

system is non-causal

if its impulse response is

(a) anu n- 2)

(b) u n )

c)

n

2

u(n)

(d) a ~ u n + 2 )

13. u(t) denotes tlle unit step function, i.e.,

u(r)=lforr; , .o

u t )=Ofor t


7/46

10. ORR tl •fi'li


8/46

•

17.

:x: (n)

:

0

•

_

What is the fundamental frequency

of

the discrete-time square wave, as shown -

in the above figure '

(a)

(b)

(c)

n radian

d

2

ra •an

d

ra 1an

4

(d) 0 radian

18 When a continuous"time signal x(l) is

sampled, what• will he

the sampled

signal

?

•

a) I t

is a product of

x(r)

and an

impulse train

(b)

c)

l

t is a

product of

.x r)

and a unit

signal

It is a product

of x l)

and a

ramp

signal

(d) It

is

a product

of

x(t) and a unit

pulse train

19. For a tachometer. e t) is the rotor dis

placement. e t) is the

o u t p ~ t

voltage and

K, is the tachometer cunstant. Which of

the folluwing represents its transfer

function '

K

1

·s

2

(b)

K,

'

(C)

K

'

'

(d)

K,

P.DTQ·.I FFO

- A

8

20.

-H,

-H,

0

"

0

c

c

With refcrcn : , , = n ~ ) l [ f l

h i ~ h one

of


is correct for t]le system represented

by the block diagram shown in the

above figure?

(a) Open luop is stable but dosed loop

unstable

(b)

Open

loop and cluscd loop both are

unstable

(c) Open loop and dosed loop buU1 are

stable

(d) Open loop is unstable but

closed

JOup

stable

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9/46

17.

X (11)

'

'

1111 Ill

II

TillP. n-Ilml

;-.t-J--m-111

TJ-LI

~ m

B'

Til-14f4ffi li:f

(b) K,

'

(d) K,

20.

21.

'

-H,

•

l f 2

0

>

0

'

G c

3m:

fu:m ir

lJ'it ~ ~

~ i t ;

t'I'"'NI

.if f.1'•1 Poi Rid if WiT

t'

(d) W T 'n' T

3WWit t ~

;;R mT

-·

A - P DTQ J FFO

•

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10/46

22.

23.

R(s)

'

Gj) ·

I K I

c 50

(o)

O.OK

10

R s)

C s)

•

s(s+4)

Consider the following statements, with

respect

to

the unity feedback system

shown in the above figure :

I. The characteristic equation IS

? 4s 16=0.

2. The loop transfer function ts

16 •

s(s+4)

3. The natural frequency of

oscill


11/46

22.

23.

R s)

· ~

.

:..l) -I

C(s)

I

'

3>'1 f W t < > W f t ~ ~

0·25

t

I

OJq>fm

~ i f i f ~ i t ~ ~

t

(o)

~

1, 2

am:

3

(b) - ~ 1 . 2 , 3 a i t t 5

( )

~ 1 . 2 3 aih:4

d) I, 2, 3, 4 3ft


12/46

•

26. Which one of the following is correct ?

Within a conductor

canying

a Cllrrent ' '

with

a

constant current density across its

cross-section. the magnetic field strength

'H' at any distance

r

from the centre

of

the conductor (radius of the conductor

is 'R') is given by

[,

H

(2nR)

(b)

lr

- (''"')

c)

H _ lr

-

(2•R )

[ ,

d)

H-p;R )

- 2nR

4

)

27. Which one

of

the following is correct

Giyen the field

E=(- ~ ~ a , in s ~ r i -

cal coordinates, the potential of point

A 2, n, ~

with respect to

point

B 4, 0, ")is

· a) 4 V

b) - 4 v

c ) - 3V

(d) 3 v

2&. Match List I with List II and select the

correct answer using the code given

below the Lists:

List I

List II

(Quantity)

(Expiession)

A. Power flow density

L

E>H

E

B. Impedance of media

2.

H

C. Joule heating

3 E·H

D. Velocity of light

4.

E

i i

P DTQ J FFO

-

A

12

Code;

A

B

c

D

(o)

I

2

3

4

(b)

4

2

3

I

(o)

I

3

2 4

• d)

4

3

2

I

·

f

..... __

__

H

= ax Hx

-

oy H, represents

ilio

H-field in a transverse plane

of

an em

wave travelling in

the

Z-direction, then

what is the E -field in the

wave?

Zol1xHy- dy Hx

J

b)

Zol1xHy

+

' JyHx

J

(o)

Zol-1xHy-' JYHx

J

(d)

Zol-

-;_ '

Hy

+

dy Hx

J

30.

For a material with conductivity

G

=

w-

2

s/m

and e =

3E

0

,

at

what frequencies the

conduction cur:ent density will

e

equal

to displacement current density ?

I

- MH

60

b)

60MHz

(o)

6·0MHz

d)

I

M H ~

6

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13/46

26.

(NIH;fl

K t) i t

:erT'Q I

&c:: i l ; < l f R m ~ ~ ~ 1

11

mft

¢ r 'Ij;itn

( ~ )

~

l .

ExH

2.

H

13.

A B C D

a) 34

b) 4 2 3

,,,

3

(d) 4 3

2

2

4

1

c .... ->

.... '-

2?. ~ I « H=axHx-ayHy rr

7

1

(•)

- MH,

60

{b)

60 MHz

c)

6-0 MHz

1

(d) -

MHz

6

A -

P DTQ J FFO

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14/46

31. Which one

of

the following stalliments

is correct?

The condition which does not guarantee

distortion less transmission is

.

(b)

at low frequencies. R > > mL and

G>>WC

at high frequencies,

R < < wL

and

G WC

C=

GL

R

(d) R=G=O

32. By which one

of

the following modes

the

rectangUlar cavity resonator cannot

e

excited ?

a) T Eon

(b)

TE OI

c)

™110

(d)

T E

110

33. What is the type

of

wave impedance

of

a waveguide operating in T mode at

frequencies below cut

off

frequencies?

(a) Complex

(b) Pur-ely reactive (capacitive)

(c) Purely reactive (inductive)

(d) Purely resistive

34. If the radiation elecuic field at the

point (r, fJ, ljl) due to a short dipole

antenna located -at the origin is

E.

then

what would e the field' at the point

2r, 8, 4 )

?

P·DTQ J FFO

-

A

l

.

b)

E

8

E

4

E

2

d)

E.

I

3S. Which one

of


is

oorrect?

For an intrinsic semiconductor, the

conductivity at any given temperature

(except at absolute :rem) is

(a)

Zero

(b) Depends upon the Fenni level

(c) Mainly due m the electrons

(d) Due to both electrons and holes

36, Which one

of


is correct ?

Hall i:ffect occurs when

•

longi rudinal

magnetic

field

applied

00

•

conductor

carrying

current

(b)

•

transverse

magnetic field

applied

00

•

conductor

carrymg

current

(c) a rransverne electric field is applied

to a conductor carrying current

(d) a temperature gradient exists across

a conductor carrying a current

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15/46

31. f.1qofdeyl'1 i t ~ a -

"""" w ""'

t

'

(a) f.n:

:aflf>il -;f;'t

"11 ffi

f


16/46

37. Which of the following statements are

correct for a super

conductor?

L A super conductor

S

a perfect

d i a m ~ g n e t

2

A super condu_ctor becomes a

nonnal

metal when an electric field

is applied.

3. A supcr conductor expels magnetic

flux from within its volume.

Select the correct

code given below :

a) I, 2 and 3

b)

and 2 only

c)

2

and 3 only

d) 1 and 3 only

answer using

the

•

38. Consider the following statements :

A dielectric material has both elec

tronic as well

as

ionic polarizations. If

the frequency

of

the alternating electric

field is increased. then

L ionic polarization will increase over

electronic polarization.

2. electronic polarization will increase

over ionic polarization.

3.

ionic

and electronic polarizations

are respectively, due to relative

displacement of:

i)

positively and negatively

charged atoms_

ii) electron cloud w.r.t. the

nucleus.

P TQ J FFO

16

. Select the corrttt answer using the

code given below :

a) only

h) 2 only

c) 2 and 3

d) I and 3

39. Which of the four contributions to the

total polarization has a large dependence

upon temperature ?

a) Ionic

b) Electronic

c) Orientational

d) Surface charge

40. Which one of the following statements

is correct.?

The

energy stored in a dielectric medium

depends upon

a) the scalar product of polarizaLion

and applied electric field

b) the scalar product of polarization

and local or internal) electric field

c) the product

of

the space charge

density of the dielectric medium

and the applied field

d) the vector product of polarization

-and applied electric field

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17/46

37.

m- *m H ~ 1 f u k ~ 1 1

it it

m

i t ~ ~ ~ ?

2. ~ " l ' " ~ S c t i

m

" ' " l f r i " ' ~ < ' 1 ' 1 i

UT JRUT

ffi\ Of'f ...-rill t I

3 Rr i l > i ~ l < t l '

it it


18/46

•

41

Which one of the fol owing statements

is correct 1

Upon alloying, electrical resistivity of

iron incrc·ases by a factor of four. In

comparison t pure iron eddy current

losses in the alloy

(a) increase by a factor of two

b) increase by a factor of four

{c decrease by a factor of four

(d) decrease by a factor of two

42

Which one of the following statements

is

correct?

The

o11idant

is t k e n ~ i n from the gas

stream by Cl\isting oxide layer

by

a

proc_ess

of

diffusion

b) bombardment

(o)

absorption

d)

adsorption

·43. The presence of which impurity material

increases the O lide etch rate several

fold?

•

Boron

b)

Phosphorus

Cadmium

d)

Sulphur


is

correct?

In "ion implementation" annealing ts

done to bring implanted ions to

(a) Interstitial sites in the lattice

b)

Substitutional sites in the lattice

(c) Top of the substrate

(d) Bottom of the substrate

P DTQ J FFO - A

18

45 Which one of the following statements

is correct ?

A CVD reactor two principal

purposes-

one is

to

provide

a

uniform

supply

of _gaseous

reactants to the

substrate surface; the other is to

(a) provide energy

to

,supply the

activation energy

(b)

absorb energy from the substrate

'5urface

c) remove reactants from the surface

{d) purify

the

surface

4 i, .Which is the most commonly used

passivation

layer?

47.

{a

Metallic layer

(b) Oxide layer

(d)

Nitride layer

Organic layer

Which one of the following statements

is correct?

In the rectifier circuit as shown in the

above figure when

v

1

t)

0,

(a) D

1

conducts' and

D

does not

{b) D

conducts and D

1

does not

{c both D

1

and D

2

conduct

(d) both D

1

and D

2

do

not conduct

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19/46

tt f.\k1f. Ma li if

'"'"J11 i

lfll"ii" ~

?

f i l ~ u IWI -..B 'R i t i l : w ~

;m: lJ"'''I if iiPilit

I fiN all j, ~

~


20/46

Cc

fo

j

r

·-+-r

c

~ ~

I

.J

D

+

Which one

of

the following relation

is correct'

The

logic operation perfonned

by

~

BJT circuit is as shown in the above

figure

is

given

by

(a) fo A B C D

b)

fo=A B C D

c)

fo=AB CD

d)

/o

AB CD

49. A Darlington pa•r consists of two

cascaded

emitter

followers wherein

t e

second transistor constitutes the emitter

load for the first. Which one of the

following statements is

not

conect in

respect of the circuit?

(a)

It

has very high input impedance

(b) Gain is

{P

where

j

is the current

gain

of

the individual transistor

P-DTQ-J-FFO

- A

(c) Voltage gain is less than one since

each transistor is connected in the

eminer foUower configuration

(d) Overall leakage current

is

very low

50. For a BIT the biasing circuit should be

designed so that

it

is stable (with very

little change

in

de operating condition)

when the following

change wit

varia

tion in temperature :

Here, with respect to which

of

the above

parameters, biasing

is

Stabilized ?

(a)

I

only

(b) I and 2 only

(c) 2

and

3 only

(d) I, 2 and 3

51.

f

the differential voltage gain and

the

common

mode

voltage

gain

of

a differ

ential amplifier are 48 dB

and

2

dB

respectively, then

what

is the value

of

CMRR?

(a)

3

dB

b) 24 dB

c) % dR

(d)

50

dB

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21/46

.

(o)

.. &at ~ ~ i t R: it

< > ~ M < t > R < l a

iJ.rr

fm:rit

f . ; - ~ ~

(

D

%(de 9 1


22/46

+12V

2K

c+

B

~ ) C r .

-?

(a) Gain== 10,

ft.==

1

Hz

fH 1M z

(b) Gain=IO,ft .=100Hz,fH=1MHz

(c)

Gain==

1000, ft.= 100Hz,

fH== 10 MHz

(d) Gain= 10, ft.== 1

Hz,

fH I

kHz

55, Which

one

of the following statements

is correct 7 ·

In a nonnalized Chebyshev low-pass

filter, the de

response

{a) is

always unity

b) is

always

less dum

unity

(c) may

be

unity 'or less than unity

depending upon whether the order

of the filter

is

odd or even, respec

tively

(d)

may be unity or less than unity

depending upon whether the order

of the filter is even or odd, respec

tively

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23/46

Sl.

+12V

H

1,.

'"'

c-.

'

\,

"

-

-

"

:;;tl\ ;ri1- m 1; '1fuN i{ m

1iJrwr;

1W

(Ic >1\l:

(I'

al

'liT

l 1'f 'lliT

t ' (

lFl ~

B

oiR .

~ · B E

0·5

V 1 :'1'

" Tf1R

l1l1 tf '300

~

l

mA3i'R9V

(b) 2 rnA. oil< 6

v

(c) 2·5 rnA

oil<

4·5

V

(d) 4 rnA 1ft\ 0 v

53.

' ['it


24/46

56.

Consider

the

following statements :

57.

The quartz crystals used in oscillators

have •

I.

a high value

of Q.

2. stable characteristics with respect

to

time and temperature varimion.

3. two resonant frequencies, viz.,

series

md

parallel.

Which of these statements are correct?

(a) 1

and

2 only

(b) 1 and 3 only

(c)

2

and

3

only

{d) 1, 2 and 3

; ;:::t=C>-

r

Which of the following can

be

used

_as a- replacement for the logic circuit

shown ahove ?

{a)

ZerO NAND

or

NOR gate

(b) Single NOR gate

'

(c) Single NAND gate

{d) One NAND gate and one NOR

g•re

P DTQ J FFO

- A

24

58. Which one

of

the following

ts

equi

valent to the Boolean express1on

- - -

Y=AB+ BC+CA?

•)

Y=CA

-

- -

(b)

Y=BC+CA

- -

-

(c)

Y=AB+BC

- -

(rl)

Y=AB+CA

59.

Consider the following logic families:

'·

.

I_

TL

2 ECL

3. CMOS

Arrange

them

m order

of

decreasing

power

c;lissipation.

(a) 3, 2, l

(b) 1,3 ,2

c ) l , 2 , 3

(d) 2, 1, 3

tnot

used

'

•

c

·

,,

· •

•

· '

•

·

0

'--<

•

·

- --1=

•

••

•

'

What is the outp-ut

of

the code

convener

constructed using

a 4

bit full-adder MSI

circuit as shown in the above figure?

(a) 2-4-2-1

code

(b) Excess-3 code

(c) Biquinary code

(d)

EBCDIC code

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25/46

•

56.

f.i'""' Mfi\l


26/46

61. Which one of the following s ~ t m m s

is correct?

A three input multiplexer wi l require

(a)

A

minimum

of

two stlect

l i n ~

and one output line

b)

One select line and

one

output

line

(o)

Three select lines and

one output

ljne

(d) Two select lines

and

two


27/46

61 f . I ~ < ~ R l R ~ a ~ i t « ~ u;

•'lfFif


28/46


29/46

'

66. f.t"" HRlt.-,

ADCs

1i'r 'ii'Tl'i:? ; amm

•

69.

¥ n -.iih:i'f 9it,

i't

B Cf.: iCft

31'R

'(1+114>\"'ili

b)

(d)

m


30/46

-

73. A

message

source produces five

symbols with probabilities

of

occurrence

t•

i· and

k .-espedivcly. What ·

is the value of entropy of source ?

(a) (j.S bits/symbol

b) 1·025 bits/symbol

(c) 1·875 bits/symbol

(d) 2-375 bits/symbol

74 In a TV system, there are 525 lines per

frame and the picture rate is 30/sec.

What is the value of sync frequency

1

'

30

pulsesfsec

b)

525 pulses/sec

1555 pulses/sec·

d) 15750 pulses/sec

75. Match List I

with

List ll and

sele


31/46

'

73. ~ tfihr -.i'rr t

' '

a) fu- '{


32/46


is c o r r e ~ r

-'With a clock f r e q u e n ~ y of 3MHz, the

execution time for the insti-uction "STA

addr" of 8085 will be

(a) 4333 ns

(b) 3975 ns

c)

3115

ns

d) 3960 ns

·81. Which one

of


is correct

?

A microprocessor program written in

assembly language is a:anslated into

machine language. The number

of

instructions in the machine language

when compared with the number of

instructions in assembly language is

(a) More only

b) Same

(c) Less only

{d) Either more or kss

82. Consider the following:

The 16 bit register/register-pair which

cannot be Stored in stack using PUSH

instruction

is

, 1. HL

2.

SP

3.

PSW

4.

PC

.

Select the correct answer using tlle

code given below :

(a) .1 and 2

(b) I and 3

(c) 2 and 3

(d) 2 and 4

P DTQ .1 FFO - A

83. Which one

of


is correct"

The

1/0

Method n ~ e in a micro

cOntroller is

(a) Hand shaking

b) Jnten:upti':'g

C) Direct Memory Access

(d) All three

of

the above

84

Which one

of

the

followi11g

statements

is

Correct ?

Temperature cGefficient of a lhcnnistor

"

(a) High

and

negative

(b)

High and positive

- c) Low and negative

d)

Low

and positive

85. Consider he following :

Measurement of currents of more than

lOA requires

J. CT

2. l T

•

3. Ancnuator

4 Hall effect probe

Select the correct answer using the

code given below :

(a) J only

(b) I or4

c )2o r3

(d) 3 or 4

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33/46

80. 8085

>M

~ ~ T '"STft. addr

&;

ffiit 011q

1 < ' 1 ~

'f.Ti'f

'f' T i'rm ,

~ 3

MHz

,,

(a)

4333 ns

(b)

3975

ns

(c) 3115

(d) 3960 ns

81.

~ . ;

&;


34/46

'

86. A thermocouple ammeter gwes full

scale denection for

a

current of 10

amp.

'Nhen it reads one fourth of the scale,

then what is the current through

the

meter?

(a) 5·0 A

(c) 3·7 A

(d) 2·5 A

87. Match List T with List

If

and select the

correct answer using the code

g.tven

below the Lists :

List I List II

'

(Transducer)

A.LVDT

B.

Strain

gallge

C.

Tacho

generator

D. Phase

meter

Code;

•

A

2

(b)

2

(o) 3

(d)

5

B

4

4

I

I

P DTQ·J FFO

A

(Appropriate

sigrw.l

Conditioner)

I.

Anillog amplifier

2. Phase-sensitive

detector

3. Logarithmic

amplifier

4. Instrumentation

amplifier

5.

e r o ~ c r o s s i n g

deteCtor

c D

I 5

3

5

4

2

4

3

34


is

not

correct ?

(a) Correctness m measurement re

quires both accuracy and precision

(b) Reproducibility and consistency are

e ~ : : p r e s s 1 n s that best describe

Jl'i ecision. in measurements

c) It is not possible to have prectse

measurements which are not

accurate

(d) An instrument

with·

2 .accuracy

is beuer than another with

5

accuracy

89.

What is the power factor

of

an a.c.

circuit under resonance

1

(4)

unity

b) 0·8 leading

(o)

0·5 leading

(d) 0·5 lagging

90. Match List I with List II and select the

correct

answer

usmg the code given;

below the

Lists :

List I

Bridges)

A. MaxweU

B. Hay

C. Shearing

D Wien

Code

A

4

b)

I

(c) . 4

d)

I

B

3

3

2

2

List If

Measurements)

1.

Frequency

2.

Capacitance

3. High 'Q' coil

4. Inductance

C D

2 I

2 4

3 I

3 4

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35/46

86

~ 'ffi"i '3lll'

10

amp m


36/46

91

The A to D converter used in digital ,

instruments could be:

I.

successive approximation converter

' '

. flash co;mvcrtcr type

3.

dual slope

convener type

What is the correct sequence of the

increasing order

of

conversion

time

taken by these types?

(a)

I _ : 2 3

b)2-l-3

c) 2 3- 1

d)

1-3-2


iS

correct?

In distortion factor meter, a

filter

is used

10

suppress

(a) d:c. component

(b) odd honnonics

{c) even honnonics

(d) fundamental frequency component

93. Which

of

the following units are present

in a spectrum analyzer?

1.

MiXer

2. Saw-tooth generator

3. Local oscillator

Select the correct answer m:ing the

code

given below :

a) 1 only

b) I and 3 only

c) 2

and

3

only

(d) l , 2 and 3

94.

What does the vertical line between

open circuit characteristics and zero

power factor characteristics

of

a

s y ~

chronous generator reprc.'Sent? ·

•

{a) voltage drop due

to

synchronous

reactance at rated current

b) voltage drop due to leakage react·

ance

at

rated current

{c) induced voltage in armature due to

resultant flux

(d) induced voltage in armature due to

field flux alone

P DTQ J FFO - A

36

·95. The industry-load on a three-phase

2200-volts supply line is 1200 kW at a

lagging power-factor

of 0·6.

In order

to

raise the line power-factor to

unity (neglecting

ll 1

the losses), what

is the kVA rating of a synchronous

condenser installed in parallel with the

load

and,

the

k

VA

rating

of

an

altemator

required to supply the new total load

?

a)

OO

kVA and 800 kVA respectively

b) 1000 kVA and 800 kYA respec-

tively

(c) 1200 kVA and 1000 kVA respec

tively

(d) 1600 kVA and 1200 kVA respec

tively

96..Match

List

I

with

list

I I

and select the

correct answer using he code given

below the i s t ~ :

List I

Motor)

A. Capacitor start

induction· motor

B.

Capacitor

start-

capacitor run

inductiOTl

motor

C.

Penmment

capacitor motor

D. Shaded pole

moto(

Code.-

A

a) 4

(b) 2

c)

4

d) 2

B

I

3

3

j

List

Charactelirtics)

c

3

I

I

3

I.

2

3.

4.

Low

starting

torque

High starting

torque

High starting

torque, better

power' factor,

better

efficiency

Inherently

self starting

but very

small starting

torque

D

2

4

2

4

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37/46

91. '114ti>i'i if 9 ;Jffi AID qf


38/46

97

If under norma saturated condition in a

power transf


39/46

97. 'lf ~ R i f < t h < > ~ i ; f s f o l a r'ftr


40/46

102

103.

'

WA

,.

0

'

'

.,

A MOSFET rated for

15

A, carries a

periodic curren.t as shown in the above

figure. The ON state resistance of

the MOSFET

is

0-15 ohm. What

is

the

average

ON

state loss in the MOSFET?

(a) 3 · 7 ~ W

{b) 7-5 w

c)

15·0 W

(d) 30·0

w

In the single phase diode bridge_re.:Lifier

as shown

in

the above figure, the load

resistor

R=50 ohms. The

011rce voltage

V 200sinWI. wherew d n -x 50 radians

per

second. What is the power dissipated

in the load

resistor?

3200

w

•

(b)

400w

•

400 w

(d)

800 w

P-DTQ-J-FFO - A

104.

Q

''

L

7

'

T

A voltage commutation circuit is shown

in the above figure.

The

tum

off

time of

the SCRs is 50 micro-second. A safety

margin of

2

is to

be

incmporated. What

will be the minimum value of capacitor

to

be provided for proper commutation ?

{b)

1·44 pF

c) 0·91 J.lF

(d) Q.72 i F

105. _ three phase semiconverter feeds the

armature

of

a . >eparately

exciteo;J.

d.c.

motor supplying a non-zero torque. For

steady state operation, the

motor

armature cun:ent is found to

drop to

zero

at certain instances of time. At such

instances the voltage assumes- a value

that is

(a) e q u < ~ l to the instantaneous value of

dle a.c. pha-;e V(tltage

(b) equal to the instantaneous value of

the motor back e.m.f.

(c) arbitrary

(d) zero

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41/46

'"'

15

A ~

~ 9 if:.1 MO.SfET

ir Jl1 : io

m ~ f o m i t ¢ i f j f f i ~ l l \ •

-mfr

t I

MOSFET

'f;1

"If"

~ , . . ; - r 'J"fuir'l

0

15 ohm

t I

MOSI'ET

ii ii11i

til

,.

' ' ~ '1 11 ' -

(a) Vi.i

\V

( j 7 j w

(t) 15-0W

(d: 30·0 w

1:%-%'11 rlr6

ir,J ..:-

;;Jm

fif: :om: t m " m l7f

t

;m

~ f i l > : i ~ » =SO

ohm> t otJ-

v

=2C(l

sm w t.

IO'i

w

=

2lf x

s

twA

~ ~ · -

'; ] (

/?il% i V C H ' I ' l f ~ ?

3 2 ~ 0

IV

,.

,:,Jo

{bl ·

'

wo v

T

'

:m;

m

'i 1l. F 't'Rm f < l < t , q f l • 4 ~

fu;r.IT

lJ'IT

%I

SCR 1i;

fult

•W 'lill'f

5 D ~ ~ ~ I 2 f r f ~ ; J F

e_fi 1fild


42/46

•

,

106. In which type of motor

h c ~ t a t i c

dynamic braking

is

veJy effective

?

•I

Cumulatively

compounded

DC

motor

(b)

DC series motor

(c) DC

~ u m

motor

(d)

Separately excited

de

motor

107. What are the advamages of oil-filled

cables

?

(a) No ionization, oxidation and forma

tion

of

·voids

(b) Possibility of increased temperature

ungc in service

c) Higher maximum

permissible

stre,ses

d) All

of the

above

For the power system network shown

ahove, the zero-sequence rcacLances in

p.u. are indicated. What is the zero

sequence driving point reactance of bus

3 in p.u.

1

a) 0-12

(b) 0-30

(c)

0 W

(d) 0·20

109. Thc1·c are 20 discs in the string of

.rnsulators of a 3-phase, 400 'kV

transmission line. String efficiency is

80 . What is the value

of

the maximum

vollage across any disc ?

P-DTQ-J-JIFO

- A

42

. (a)

16 kV

(b)

25 kV

c)

J3 x2S kV

(d)

25 kV

13

110.

What

is

the primary considemtion

in

deciding the conductor si7-C

of EHV

lines'?

(a) Voltage drop

b) Current density

c) Corona

d)

Voltage drop and current density

111. Which two

items

are connected by

a

tic

hne?

' '

Two power stations

(b)

Power station and load

centre

c)

Two generators

(d)

Systems

in

two areas

112.

Which

of

the

following relays is used

for

the protection of a series compensated

EHV line?

(a) Impcdanc:e relay

(b) Reactance relay

{c) Mho

relay

(d) Static distance relay/Microproces

sor based relay

113.

What is

the

order

of

the reactive power

consumed by an

HVDC converter?

(a)

Equal to real power

(b)

Equal to

25

of real

power

(c)

Equal to

50

of re


43/46

'

06. % 1" 'l9iK ft

"lim:

i> •

~ ~ ~ ~

(a)

~ f i N DCli'm

(b)

D C ~ - . f r :

(c) DC m: :i'r:fuR

l ~ ~ w o n m f t r

Rit

111 H V D C ~ m 1 ~ ~ 1 l f r n

tl ilfhm t '

{a) ~ 1 l f r n i t ~

b ) · ~

j fu;

t 25%

t

OfUOI1:

(c) E

1M 5[1%

it

il\i1'\

(d) 1:19; il; 75% it


44/46

D i r r c t i i m ~ :

Each of the next Seven (07) items consists of

two statemems,

Qne

labelled as the 'Assert10n

(A}' arrd the other as :Reason (R)'.

You

arc to

examine these

tw


45/46

•

f . \ i ~

:

f

'il'f

filw

'''"'hfr

~ t m

~ f

~

'

lf"fi1''

Offill'\ "

..,

• , '

m

r i'i

Ii'r.r

~ ' f l ' l ; r t I

116. 'f'l"

:M

:

'l'mrl ~ tmr "·'·

; f r t i ~ ~ t l

~ (R}: ' < V ' < i l l ~ £ r r A A l l '

• ; f t d ~ i\ q;,;

q;;:([f I

45

117. 01"1

(A) :

~ li'>T'f z . ~

>:'if ~ H I

1l1(lJ[

·:R:

:

-fit; Z - - ~ t

m 1ft /-ifRi ' f8 'iffiiT t

'"" ~ « ~ ~ l > f k < 1fOiT 1fl

fo-m1 t I

T f l T [ \ R ~ : ~ ~ " 1 ~ 1 2


46/46

it .i f

t. 'ff

i. : P-D

TQ-

J-FF

O

'

ffi1<

t>l il1"

1>41

.A

ff f

f'IT

f'l

'\l<

t

i ' l

f . i

~ : i l

~

'

JOfJ

.

' m

:n f

~

i

t ~

om:.

ar 'lf

V

t .

. ' f

ffi«>o

ll1

i

t

fm1: f

i f i

i

t; si I

~

-.i1

ft>n

Oi"T"o

/IT I

(i)

' ~ i f if;

W

~ q ; f < i i

t . ; ; ~

I

l < J O

iiT<

I g

('itq; n

'l it

fom

;

ftc

:

.-.-..:

ll ;'l'

liR

i t

m

~ f.

o-- :

% - ~

(0·3

3)

W: i t

¥

'1 i'f

electrical engineering objective questions part 11

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