EduRev

Courses

Get the App Signup / Login

Welcome Back

Forgot Password?

New User? Sign Up

Create your account now

I accept the Terms & Conditions.

Already Have an Account? Login

Technical Test SSC JE: Electrical Engineering (EE)- 15

100 Questions MCQ Test Mock Test Series for SSC JE Electrical Engineering | Technical Test SSC JE: Electrical Engineering (EE)- 15

Description

Attempt Technical Test SSC JE: Electrical Engineering (EE)- 15 | 100 questions in 100 minutes | Mock test for Electrical Engineering (EE) preparation | Free important questions MCQ to study Mock Test Series for SSC JE Electrical Engineering for Electrical Engineering (EE) Exam | Download free PDF with solutions

QUESTION: 1

The smallest change in a measured variable to which an instrument will respond is

A.
accuracy
B.
resolution
C.
precision
D.
sensitivity

Solution:

QUESTION: 2

Two bulbs marked 200 wtt-250 volts and 100 watt-250 volts are joined in series to 250 volts supply. Power consumed in circuit is

A.
33 watt
B.
67 watt
C.
100 watt
D.
300 watt

Solution:

QUESTION: 3

Hysteresis losses in a d.c. machine are proportional to

A.
B.
N
C.
N₂
D.

Solution:

QUESTION: 4

Torque/ weight ratio of an instrument indicates

A.
selectivity
B.
accuracy
C.
fidelity
D.
sensitivity

Solution:

QUESTION: 5

Series reactors are used to

A.
improve the transmission efficiency
B.
improve the power factor of the power system
C.
improve the voltage regulation
D.
bring down the fault within the capacity of the switchgear.

Solution:

QUESTION: 6

What is the range for a 3(1/2)digit digital voltmeter ?

A.
0 to 1999
B.
0 to 1500
C.
0 to 999
D.
0 to 19999

Solution:

QUESTION: 7

........ is the region of a transistor which has highest conductivity.

A.
Emitter
B.
Base
C.
Collector
D.
None of these

Solution:

QUESTION: 8

Two coils have self-inductances of 0.09 H and 0.01 H and mutual inductance of 0.015 H. The coefficient of coupling between coils is

A.
0.060
B.
0.5
C.
1.0
D.
0.05

Solution:

QUESTION: 9

Two resistances R₁ and R₂give combined resistance of 4.5 ohms when in series and 1 ohm when in parallel. The resistance are

A.
3 ohms and 6 ohms
B.
3 ohms and 9 ohms
C.
1.5 ohms and 3 ohms
D.
1.5 ohms and 0.5 ohms

Solution:

QUESTION: 10

In a star-connected system without neutral grounding, zero-sequence currents are

A.
zero
B.
phasor sum of phase currents
C.
same as rms value of phase currents
D.
same as peak value of phase currents

Solution:

QUESTION: 11

Sensitivity of a voltmeter is given as

A.
W/V
B.
reciprocal of full-scale deflection current
C.
both (a) and (b).
D.
none of these

Solution:

QUESTION: 12

If one of the central springs of a Permanent Magnet Moving Coil ammeter is broken then when connected it will read

A.
zero
B.
Half of the correct value
C.
Twice the correct value
D.
An infinite value

Solution:

QUESTION: 13

The positive sequence current of a transmission line is :

A.
always zero
B.
1/3 of negative sequence current.
C.
equal to negative sequence current
D.
3 times negative sequence current

Solution:

QUESTION: 14

The teeth in the armature of a dc machine are sometimes skewed. This is done to reduce

A.
hysteresis loss
B.
copper loss
C.
eddy current loss
D.
vibrations

Solution:

QUESTION: 15

When a line-to-ground fault occurs, the current in the faulted phase is 100 A. The zero-sequence current in this case will be :

A.
Zero
B.
33.3 A
C.
66.6 A
D.
100 A

Solution:

QUESTION: 16

Resistance across A and B in the circuit shown below is

A.
R
B.
3 R
C.
4 R
D.
5 R

Solution:

QUESTION: 17

In a CRT the highest positive potential is given to

A.
focusing electrodes.
B.
cathode
C.
vertical deflection plates
D.
post deflection acceleration anode

Solution:

QUESTION: 18

the purpose of the synchronising control in a CRO is to

A.
focus the spot on the screen
B.
lock the display of signal
C.
adjust the amplitude of display
D.
control the intensity of the spot

Solution:

QUESTION: 19

Power factor of an inductive circuit can be improved by connecting a capacitor to it in

A.
series
B.
parallel
C.
either series or parallel
D.
depends on the value of the capacitor

Solution:

QUESTION: 20

In measurements made using a Q-meter impedance elements should preferably be connected in

A.
star
B.
delta
C.
series
D.
parallel

Solution:

QUESTION: 21

Wagner Eearth devices in ac bridge circuits are used for

A.
Shielding all the bridge elements from external magnetic field
B.
Eliminating the effect of stray capacitance
C.
Eliminate the effect of earth capacitance
D.
Minimizing the effect of inter component capacitance.

Solution:

Wagner’s earth devices are used in ac bridge circuits to eliminate the effect of earth capacitance.

QUESTION: 22

When the supply terminals of a dc shunt motor are interchanged

A.
the motor will stop
B.
the motor will run at its normal speed in the same direction as before.
C.
the direction of rotation will reverse
D.
the motor will run much faster in the same direction

Solution:

QUESTION: 23

The current of a single-phase load drawn from a 3-phase system has:

A.
Zero-sequence component of current as zero
B.
Negative-sequence component of current more than positive sequence component.
C.
Positive-negative-and zero-sequence components equal.
D.
Negative-sequence component of current less than positive-sequence component.

Solution:

QUESTION: 24

Systematic error are

A.
instrumental errors.
B.
environmental errors.
C.
observational errors.
D.
all of the above

Solution:

QUESTION: 25

The minimum number of wattmeter (s) required to measure 3-phase 3-wire balanced or unbalance power is

A.
1
B.
2
C.
3
D.
4

Solution:

QUESTION: 26

The voltage coil of a single phase house energy meter

A.
is highly resistive
B.
is highly inductive
C.
is highly capacitive
D.
has a phase angle equal to load power factor angle

Solution:

QUESTION: 27

Which one of the following methods decreases the error due to connections in a dynamometer type wattmeter ?

A.
Using bifilar compensating winding in place of current coil.
B.
Using non-inductive pressure coil circuit
C.
Using a capacitor across a part of high resistance of pressure coil circuit
D.
Using a swamping resistance

Solution:

QUESTION: 28

If the positive-, negative-and zero-sequence reactances of an element of a power system are 0.3, 0.3 and 0.8 pu respectively, then the element would be a

A.
synchronous generator
B.
synchronous motor
C.
static load
D.
transmission line

Solution:

QUESTION: 29

A separately excited dc generator is feeding a dc shunt motor. If the load torque on the motor is halved approximately

A.
armature current of both motor and generator are halved.
B.
armature current of motor is halved and that of the generator is unaltered.
C.
armature current of generator is halved and that of motor is unaltered
D.
armature current of both motor and generator are unaltered

Solution:

QUESTION: 30

A manganin swamp resistance is connected in series with a moving coil ammeter consisting of a milliameeter and a suitable shunt in order of

A.
minimise the effect of temperature variation.
B.
obtain large deflection
C.
reduce the size of the meter
D.
minimise the effect of stray magnetic fields

Solution:

QUESTION: 31

If starter is not used dc motor for starting, it will draw a starting current which

A.
is many times its rated full-load current
B.
will produce excessive voltage drop in line.
C.
may damage the armature and commutator
D.
will produce very low starting torque

Solution:

QUESTION: 32

The deflecting torque of a moving iron instrument is

Solution:

QUESTION: 33

If all the sequence voltages at the fault point in a power system are equal, then the fault is a

A.
three-phase fault
B.
line-to ground fault
C.
line-to-line fault
D.
double-line-to ground fault

Solution:

QUESTION: 34

A set of independent current measurements taken by four observers was recorded as : 117.02 mA, 117.11 mA, 117.08 mA and 117.03 mA. What is the range of error ?

A.
±0.045
B.
±0.054
C.
±0.065
D.
±0.056

Solution:

QUESTION: 35

Two coils having equal resistances but different inductances are connected in series. The time constant of the series combination is the

A.
Sum of the time constants of the individual coil
B.
Average of the time constant of individual coils
C.
Geometric mean of the time constant of the individual coils
D.
Product of the time constant of the individual coils

Solution:

QUESTION: 36

The zero-sequence circuit of the three-phase transformer shown in the figure is

Solution:

QUESTION: 37

The accuracy of Kelvin’s double bridge for the measurement of low resistance is high because the bridge

A.
uses two pairs of resistance arms.
B.
has medium value resistances in the ratio arms.
C.
uses a low resistance link between standard and test resistance.
D.
uses a null indicating galvanometer

Solution:

QUESTION: 38

The octal equivalent of decimal 98 is

A.
89
B.
98
C.
142
D.
241

Solution:

QUESTION: 39

has the dimension of

A.
time
B.
capacitance
C.
inductance
D.
resistance

Solution:

QUESTION: 40

Steady state stability of a power system is improved by

A.
reducing fault clearing time
B.
using double circuit line instead of single circuit line.
C.
single pole switching
D.
decreasing generator inertia

Solution:

QUESTION: 41

The transistor is usually encapsuled in –

A.
Graphite powder
B.
Enamel point
C.
Epoxy resin
D.
Any of the above

Solution:

QUESTION: 42

An alternating e.m.f. is applied to a pure inductance such that inductive reactance is 10 W.
If the frequency of a.c. is doubled, the reactance will become

Solution:

QUESTION: 43

The positive-sequence current for a L-L fault of a 2kV system is 1,400 A, and corresponding current for a L-L-G fault is 2,220 A.

The zero-sequence impedance of the system is

A.
62.75W
B.
4.5275W
C.
5.275W
D.
0.5275W

Solution:

QUESTION: 44

An RLC resonant circuit has a resonance frequency of 1.5 MHz and a bandwidth of 10
kHz. If C = 150 pF, then the effective resistance of the circuit will be

Solution:

QUESTION: 45

Match List I with List II and select the correct answer using the codes given below the lists:

A.
A
B.
B
C.
C
D.
D

Solution:

QUESTION: 46

For the same voltage drop, increasing the voltage of a distributor n-times.

A.
reduces the x-section of the conductor by n times
B.
increases the x-section of the conductor by n times
C.
reduces the x-section of the conductor by n² times
D.
increases the x-section of the conductor by n²times.

Solution:

QUESTION: 47

A single – Phase, 200 V alternator has armature resistance and reactance of 0.8W and 4.94W respectively. The voltage regulation of the alternator at 100 A load at 0.8 leading power factor is

A.
7%
B.
– 8.9 %
C.
14%
D.
0%

Solution:

QUESTION: 48

The insulation coordination for UHV lines (above 500 kV) is done base on

A.
lightning surges
B.
lightning surges and switching surges
C.
switching surges
D.
none of the above

Solution:

QUESTION: 49

A SCIM having a rated slip of 4% on full load has a starting torque the same as full-load torque.The starting current is

A.
equal to full-load current
B.
twice the full-load current
C.
four times full-load current
D.
five times full-load current

Solution:

QUESTION: 50

Lightning is a huge spark caused by electrical discharge taking place between

A.
clouds
B.
within the same cloud
C.
cloud and earth
D.
any of the above

Solution:

QUESTION: 51

A network N ' is dual of network N if

A.
Both of them have same mesh equations
B.
Both of them have the same node equations
C.
Mesh equations of are the node equations of the other
D.
KCL and KVL equations are the same

Solution:

QUESTION: 52

Which of the following is usually not the generating voltage ?

A.
6.6 kV
B.
9.9 kV
C.
11 kV
D.
13.2 kV

Solution:

QUESTION: 53

Post-deflection is required in CRO, if input signal frequency is

A.
less than 1 kHz.
B.
less than 1 MHz.
C.
below 10 MHz.
D.
above 10 MHz

Solution:

QUESTION: 54

In a resistance loaded, RC coupled amplifier the D.C. component is blocked by –

A.
Transistors
B.
C_C
C.
R_B
D.
R_C

Solution:

QUESTION: 55

An higher scale ammeter is used to measure too low current. The measurement would have low

A.
precision
B.
accuracy
C.
resolution
D.
all of these

Solution:

QUESTION: 56

Dominating harmonics in IM is

A.
(6n ±1)
B.
(4n ±1)
C.
(2n ±1)
D.
(8n ±1)

Solution:

QUESTION: 57

A 3-Phase star-connected symmetrical load consumes P watts of power from a balance supply. If the same load is connected in delta to the same supply , the power consumption will be

A.
P
B.
C.
3 P
D.
not determinable from the given data

Solution:

QUESTION: 58

Dead zone of an instrument is

A.
the time required by an instrument to warm up initially.
B.
the largest change of input quantity for which there is no output of the instrument
C.
the unmeasured quantity which exceeds the maximum range of the instrument
D.
none of the above

Solution:

QUESTION: 59

Which of the following components of a D.C. generator plays vital role for providing direct current of a D.C. generator ?

A.
Dummy coils
B.
Commutator
C.
Eye bolt
D.
Equalizer rings

Solution:

QUESTION: 60

What is the slope of the line due to1/jW factor in magnitude part of Bode plot?

A.
– 20 db per octave
B.
– 10 db per octave
C.
– 6 db per octave
D.
– 2db per octave

Solution:

QUESTION: 61

For the circuit shown in fig. the meter will read

A.
1 A
B.
5 A
C.
10 A
D.
25 A

Solution:

QUESTION: 62

The ratio of starting torque to full load torque is least in case of—

A.
Series motors
B.
Shunt motors
C.
Compound motors
D.
None of the above

Solution:

QUESTION: 63

An indicating instrument is more sensitive if its torque to weight ratio is

A.
much larger than unity
B.
of the order of unity
C.
much less than unity
D.
made deflection dependent

Solution:

QUESTION: 64

When a capacitor was connected to the terminal of an ohmmeter the pointer indicated a low resistance initially and then slowly came to infinity position. This shows that the capacitor is

A.
short-circuited.
B.
all right.
C.
open-circuited.
D.
weak.

Solution:

QUESTION: 65

Impulse ratios of insulators and lightning arresters should be

A.
both low
B.
high and low respectively
C.
low and high respectively
D.
both high

Solution:

QUESTION: 66

For complete protection of a 3-phase transmission line we require

A.
three -phase and three earth fault relays.
B.
three-phase and two earth fault relays
C.
two-phase and two earth fault relays
D.
two-phase and one earth fault relay

Solution:

QUESTION: 67

Hopkinson’s test is conducted at—

A.
No load
B.
Part load
C.
Low load
D.
Full load

Solution:

QUESTION: 68

The difference between the indicated value and the true value of a quantity is

A.
gross error
B.
absolute error
C.
dynamic error
D.
relative error

Solution:

QUESTION: 69

Which of the following is the fastest switching device?

A.
JFET
B.
BJT
C.
MOSFET
D.
Triode

Solution:

QUESTION: 70

Consider the protection system shown in the figure. The circuit breakers numbered from 1 to
7 are of identical type. A single line to ground fault with zero fault impedance occurs at the
midpoint of the line (at point F), but circuit breaker 4 fails to operate ("stuck breaker"). If the relays
are coordinated correctly, a valid sequence of circuit breaker operation is

A.
1, 2, 6, 7, 3, 5
B.
1, 2, 5, 5, 7, 3
C.
5, 6, 7, 3, 1, 2
D.
5, 1, 2, 3, 6, 7

Solution:

QUESTION: 71

In an Anderson bridge, the unknown inductance is measured in term of known

A.
resistance.
B.
capacitance.
C.
inductance and resistance.
D.
resistance and capacitance

Solution:

QUESTION: 72

Mho relay is usually employed for the protection of

A.
short lines only
B.
medium lines only
C.
long lines only
D.
any line

Solution:

QUESTION: 73

To measure 5 volts. If one selects a 0 – 100 V range voltmeter which is accurate within + 1%,then the error in this measurement may be up to

A.
+ 1.5%
B.
+ 2.5%
C.
+ 7.5%
D.
+ 20%

Solution:

QUESTION: 74

The full-load copper loss and iron loss of a transformer are 6,400 W and 5,000 W respectively. The copper loss and iron loss at half load will be, respectively

A.
3,200 W and 2,500 W.
B.
3,200 W and 5,200 W.
C.
1,600 W and 1,250 W.
D.
1,600 W and 5,000 W.

Solution:

QUESTION: 75

Curve A and B represent the properties for materials which have

A.
low resistance
B.
low conductance
C.
negative resistance
D.
negative temperature coefficient

Solution:

QUESTION: 76

Systematic error are

A.
instrumental errors
B.
environmental errors
C.
observational errors
D.
all of the above

Solution:

QUESTION: 77

Vibration galvanometers, tuneable amplifiers and head phones are used in

A.
dc bridges.
B.
ac bridges.
C.
both dc and ac bridges.
D.
Kelvin double bridge.

Solution:

QUESTION: 78

An impedance relay is a

A.
voltage restrained overcurrent relay
B.
voltage restrained directional relay
C.
directional restrained overcurrent relay
D.
directional restrained overvoltage relay

Solution:

QUESTION: 79

If the readings of the two wattmeters are equal and positive in two wattmeter method, the load pf in a balanced 3-phase 3-wire circuit will be

A.
zero
B.
0.5
C.
0.866
D.
unity

Solution:

QUESTION: 80

The most serious consequence of a major uncleared short-circuit fault could be

A.
blowing of fuse
B.
fire
C.
heavy voltage drop
D.
none of these

Solution:

QUESTION: 81

A distribution transformer is selected on the basis of

A.
voltage regulation.
B.
efficiency.
C.
all day efficiency.
D.
none of those.

Solution:

QUESTION: 82

Under the condition of resonance in R-L-C series circuit, the pf of the circuit is

A.
0.5 lagging
B.
0.5 leading
C.
unity
D.
zero

Solution:

QUESTION: 83

Consider the following statements associated with an energy meter.
1. It is an integrating type instrument.
2. It is an induction type instrument.
3. It uses a permanent magnet for rotation of aluminium disc.
4. it employs a high control torque.
Which of these statements are correct ?

A.
1, 2, 3 and 4
B.
1 and 2 only
C.
2 and 3 only
D.
3 and 4 only

Solution:

QUESTION: 84

In a.c. circuit, the power is consumed only in

A.
inductance
B.
capacitance
C.
resistance
D.
all the given above

Solution:

QUESTION: 85

Which portion of the transmission system is more prone to faults ?

A.
Alternator
B.
Transformer
C.
Overhead lines
D.
Underground cable

Solution:

QUESTION: 86

An ideal dc generator has a regulation of ____ per cent.

A.
zero
B.
10
C.
25
D.
100

Solution:

QUESTION: 87

The maximum power that can be distributed in the load in the circuit shown in

A.
3 watts
B.
6 watts
C.
6.75 watts
D.
13.5 watts

Solution:

QUESTION: 88

Which one of the following is the main cause of creeping in the induction type energy meters ?

A.
Friction compensation
B.
Lag/Lead compensation
C.
Overload compensation
D.
Braking torque producing system

Solution:

QUESTION: 89

The errors introduced by an instrument fall in which category ?

A.
Systematic errors.
B.
Random errors.
C.
Gross errors.
D.
Environmental errors

Solution:

QUESTION: 90

Which portion of the power system is least prone to faults ?

A.
Alternators
B.
Switchgear
C.
Transformers
D.
Overhead lines

Solution:

QUESTION: 91

At resonant frequency an R-L-C circuit draws maximum current due to the reason that

A.
the difference between capacity reactance and inductive reactance is zero
B.
the impedance is more than resistance
C.
the voltage across the capacitor equals the applied voltage
D.
the power factor is less than unity

Solution:

QUESTION: 92

Schering bridge can be used to measure which one of the following ?

A.
Q of a coil.
B.
Inductance and its Q-value.
C.
Very small resistance.
D.
Capacitance and its power factor

Solution:

QUESTION: 93

If an induction type energy meter runs fast, it can be slowed down by

A.
lag adjustment
B.
adjustment the position of braking magnet and moving it closer to the centre of the disc.
C.
adjusting the position of the braking magnet and moving it away from the centre of the disc.
D.
None of the above