KDRB Assistant Engineer (Electrical) PYQ Free Mock Test

Question 1

Who got ONV Literary Award for the year 2022

A

C. Radhakrishnan

B

T. Padmanabhan

C

M. Mukundan

D

K.R. Meera

Question 2

Which Article of the Indian Constitution relates to GST Council?

A

Article 239 AA

B

Article 312

C

Article 280

D

Article 279 A

Question 3

The book 'Waiting for Mahatma' is written by

A

R.K. Narayan

B

Ramchandra Guha

C

Mulk Raj Anand

D

Gopalkrishna Gandhi

Question 4

Where is the World Economic Forum Annual Meeting held?

A

New York

B

Geneva

C

Davos

D

Hague

Question 5

Operation Ganga is associated with

A

Conservation and Rejuvenation of River Ganga

B

Evacuation of Indians from Ukraine

C

Campaign for reducing fuel consumption

D

Evacuation of Indians from Sri Lanka

Question 6

Azad Hind Fauj is organized by:

A

Chittaranjan Das

B

Sri Aurobindo

C

Bhagat Singh

D

Subhash Chandra Bose

Question 7

Which day is celebrated as National Voter's Day?

A

January 25

B

November 26

C

January 26

D

November 25

Question 8

Dostarlimab medicine is related to which disease?

A

AIDS

B

Asthma

C

Cancer

D

Alzheimer's

Question 9

Who is known as 'the Tendulkar of Women's Cricket'?

A

Ellyse Perry

B

Jhulan Goswami

C

Sana Mir

D

Mithali Raj

Question 10

Which Country Won the Thomas Cup 2022?

A

Indonesia

B

India

C

Australia

D

Germany

Question 11

A series RLC circuit has R = 2000, L= 50 mH and C = 0.60 F and a peak voltage of 40 Vat a frequency of 100 Hz. What is the rms value of the current in the circuit?

A

20 mA

B

14.14 A

C

19.5 mA

D

14.14 mA

Question 12

For the circuit given, find the reactive power:

A

119.998 VAr

B

119.365 VAr

C

169.256 VAr

D

119.998 W

Question 13

A resistor of 10Ω, inductance 0.3 H and capacitance of 100 µF are connected across 230 V, 50 Hz mains in series. Calculate the power factor :

A

Zero

B

0.158 lag

C

0.158 lead

D

Unity

Question 14

The value of ripple factor for a full wave rectifier is:

A

√3

B

1.21

C

√2

D

0.482

Question 15

Controlling torque in indicating instruments is commonly achieved by:

A

Fluid friction

B

Eddy currents

C

Air friction

D

Springs

Question 16

A coil in wound uniformly with 300 turns over a steel ring of relative permeability 900 having a mean circumference of 40 cm and a cross sectional area of 5 cm3. If the coil has a resistance of 100 Ωand is connected to 250 V dc supply, calculate the field strength:

A

1875 AT/m

B

750 AT/m

C

1500 AT/m

D

900 AT/m

Question 17

A coil of 1000 turns is linking a flux of 0.01 Wb. The flux is reversed in an interval of 0.1 sec. Calculate the average e.m.f. induced in the coil:

A

150 V

B

300 V

C

200 V

D

220 V

Question 18

A conductor of length 150 cm moves at an angle of 30° to a uniform magnetic field of flus density 2 T with a velocity of 100 m/sec. Calculate the e.m.f. induced in it:

A

75 V

B

150 V

C

37.5 V

D

50 V

Question 19

Determine the form factor of the output voltage wave of a half wave rectified:

A

1.11

B

√2

C

√3

D

1.57

Question 20

A 240 V, 50 Hz, AC supply is applied a coil of 0.08 H inductance and 4Ω resistance connected in series with a capacitor of 8 µF. Calculate the Q-factor of the circuit at resonant frequency.

A

25

B

50

C

75

D

100

Question 21

A parallel resonance network consisting of a resistor of 50 Ω, a capacitor of 100 µF and an inductor of 300 mH is connected across a sinusoidal supply voltage which has a constant output of 100 volts at all frequencies. Calculate the resonant frequency.

A

50 Hz

B

60 Hz

C

10.06 Hz

D

29.06 Hz

Question 22

A 12 pF capacitor is connected to a 50 V battery. How much electrostatic energy is stored in the capacitor?

A

25×10-4J

B

15x10-12J

C

15x10-4J

D

3.5x10-4J

Question 23

A 40 kVA 3300/240 V, 50 Hz, 1-phase transformer has 660 turns on the primary. Determine the number of turns on the secondary.

A

42

B

24

C

48

D

9075

Question 24

Find the voltage drop across R2

A

18 V

B

12 V

C

6V

D

36 V

Question 25

Find the current I in the circuit given

A

4 mA

B

6 mA

C

12 mA

D

11 mA

Question 26

Find the equivalent resistance across the terminals A & B of the following electrical network.

A

5 Ω

B

23 Ω

C

10 Ω

D

None of these

Question 27

What is Thevenin's voltage for the given circuit with load RLoad?

A

24 V

B

18 V

C

15 V

D

12 V

Question 28

For the given network, find the value of Is, which reduces the voltage across the 4Ω resistor to zero. (Hint: Use Superposition theorem)

A

2 A

B

3.5 A

C

1.5 A

D

1.25 A

Question 29

The inverse Laplace transform of H (S)= (S+3) / (S2+2S+1) for t≥0 is

A

3te-t+e-t

B

3e-t

C

2te-t+e-t

D

4te-t+e-t

Question 30

Laplace transform of the function shown below is given by:

A

(1-e-2s) / s

B

(1-e-s) / 2s

C

2(1-e-s) /s

D

1-2e-2s / s

Question 31

The function f(t) satisfies the differential equation d2f/dt2+f=0 and the auxiliary conditions, f(0) = 0, df/dt(0) =4. The Laplace transform of f(t) is given by

A

2 / s+1

B

4 / s2+1

C

3 / s+1

D

2 / s4+1

Question 32

The star equivalent resistance of 3 resistors having each resistance = 5 Ω is

A

1.5 Ω

B

3 Ω

C

4.5 Ω

D

1.67 Ω

Question 33

Given two mutually coupled coils have a total inductance of 1500 mH, the self-inductance of each coils if the coefficient of coupling is 0.2 is

A

625 mH

B

550 mH

C

325 mH

D

255 mH

Question 34

A capacitor, used for power factor correction in a single phase circuit increases which of the following?

A

Line Current

B

Power Factor

C

Both Line Current and Power Factor

D

Neither Line Current nor Power Factor

Question 35

What is Norton's resistance for the given circuit with load RLoad?

A

30 Ω

B

13.75 Ω

C

11 Ω

D

7.5 Ω

Question 36

Which of the following tests must be performed on a transformer to determine its core losses?

A

Routine tests

B

SC test only

C

OC test only

D

Both OC and SC tests

Question 37

The efficiency of a transformer at full load 0.85 pf lag is 95%. Its efficiency at full load 0.85 pf lead will be

A

More than 95%

B

Less than 95%

C

95%

D

100%

Question 38

Two transformers of identical voltages but of different capacities are operating in parallel. For satisfactory load sharing

A

Impedances must be equal

B

Per-unit impedances must be equal

C

Per-unit impedances and X/R ratios must be equal

D

Impedances and X/R ratios must be equal

Question 39

A single-winding single phase motor has

A

Low starting torque

B

Zero starting torque

C

High starting torque

D

Starting torque equal to full load torque

Question 40

A single phase stator winding when excited with ac voltage produces

A

A single rotating field rotating at synchronous speed

B

Two rotating fields rotating in the same directions but at different speeds

C

Two rotating fields rotating at synchronous speed in opposite directions

D

Two rotating fields rotating in opposite directions but with different speeds

Question 41

What should be observed if a de shunt motor is started with an open-circuited field?

A

The motor does not pick up speed but draws a large current

B

The motor does not pick up speed but draws only a small current

C

The motor picks up fast and acquires full speed while drawing large current

D

The motor picks up fast and acquires full speed while drawing small current

Question 42

A DC generator will have maximum efficiency when

A

Eddy current losses = Stray losses

B

Hysteresis losses = Eddy current losses

C

Copper loss = 0

D

Variable Losses Constant Losses

Question 43

The speed of a DC shunt motor can be increased by

A

Increasing the resistance in the armature circuit

B

Decreasing the resistance in the armature circuit

C

Increasing the resistance in the field circuit

D

Decreasing the resistance in the field circuit

Question 44

DC shunt motors are started with a starter

A

To restrict the armature current as the back emf is zero while starting

B

To restrict the field current as the back emf is zero while starting

C

These motors have high starting torque

D

To provide residual magnetism required for startup

Question 45

In a DC machine, which of the following speed control methods is least preferred?

A

Voltage Control method

B

Field Control method

C

Armature Control method

D

Ward-Leonard System

Question 46

Which of these features can be used to identify a DC series motor?

A

A motor with low starting torque

B

A motor with thick field windings

C

A motor which can be started easily without any load

D

A motor with constant speed

Question 47

Which of the following motors is used for a 20 HP hoist motor?

A

Single phase induction motors

B

DC shunt motors

C

PMDC motors

D

Wound field DC motors

Question 48

A 3-phase 440 V, 50 Hz induction motor has 3% slip. The frequency of rotor current will be

A

1.5 Hz

B

50 Hz

C

25 Hz

D

5 Hz

Question 49

In a three-phase induction motor, the number of poles in the rotor winding is always

A

Zero

B

More than the number of poles in the stator

C

Equal to the number of poles in the stator

D

Less than the number of poles in the stator

Question 50

A three-phase, four-pole, 50 Hz induction motor rotates at a full-load speed of 1470 rpm. The EMF measured between the slip-ring terminals when the rotor is not rotating is 200 V. The rotor windings are star connected and have resistance and stand-still reactance per phase of 0.1 Ω and 1.0 Ω respectively. Then the rotor current at full load is

A

25 A

B

11.2 A

C

15.43 A

D

22.5 A

Question 51

A 3-phase induction motor is running at 3% slip. If the input to rotor is 1000 W, then mechanical power developed by the motor in

A

970 W

B

30 W

C

500 W

D

300 W

Question 52

For a large range of speed changes, which of the following speed control techniques is used in squirrel cage induction motors?

A

Cascade Connection

B

Rheostatic Control

C

Pole changing method

D

Frequency Control

Question 53

Which relay is found in a distribution transformer?

A

Polarized Relay

B

Buchholz Relay

C

High-Voltage Relay

D

Small Signal Relay

Question 54

A vessel with silica gel to prevent the moist air entering into the tank in a transformer is called

A

Breather

B

Conservator

C

Buchholz Relay

D

Vent

Question 55

A single phase 800 V/100 V, 50 Hz transformer has a maximum core flux density of 1.294 T and an effective cross sectional area of 60 cm². Calculate the number of turns on the secondary windings.

A

100 turns

B

800 turns

C

464 turns

D

58 turns

Question 56

For a uniformly distributed winding of an alternator with a phase spread of 𝛽 degrees, the distribution factor is ------- (Assume m=1)

A

sin 𝛽/𝛽

B

2sin (𝛽/2)/𝛽

C

sin (𝛽/2)/𝛽

D

sin (𝛽/2)/2𝛽

Question 57

Two identical loss-less series motors connected in series across a dc supply voltage, run at speeds of N1, and N2, then ratio of their output powers will be

A

N12 : N22

B

1 : 1

C

N1 : N2

D

N2 : N1

Question 58

Slip test is performed to determine

A

Slip

B

Positive and negative sequence reactances

C

Sub Transient reactance

D

Direct and quadrature axis reactances

Question 59

Which of the following motors running under the specified conditions will have a leading power factor?

A

Double-cage induction motor at load

B

Over excited synchronous motor

C

Under excited synchronous motor

D

Slip ring induction motor at no load

Question 60

A circular iron core has an air-gap cut in it and is excited by passing direct current through a coil wound on it. The magnetic energy stored in the air-gap and the iron core is

A

Inverse ratio of their reluctances

B

Equally divided among them

C

In direct ratio of their reluctances

D

Energy resides wholly in the iron core

Question 61

The transfer function of the system described by d2y/dt2 + dy/dt = du/dt + 3u where u is the input and y is the output is

A

(s+3) / (s²+2)

B

(s+1) / (s²+2)

C

s / (s²+2)

D

3s / (s²+2)

Question 62

Consider the following statements regarding time-domain analysis of a control system:

(i) Derivative control improves system's transient performance

(ii) Integral control does not improve system's steady state performance

(iii) Integral control can convert a second order system into a third order system.

Of these statements:

A

(i) and (ii) are correct

B

(i) and (iii) are correct

C

(ii) and (iii) are correct

D

(i), (ii) and (iii) are correct

Question 63

The characteristic equation of a feedback system is:

s3+Ks2 +5s+10=0

For the system to be critically stable, the value of K should be:

A

1

B

2

C

3

D

4

Question 64

The phase margin of a system with the open-loop transfer function:

G(s) II(s) = (1-s) / (1+s)(3+s) is

A

0°

B

63.4°

C

90°

D

infinity

Question 65

A linear discrete-time system has the characteristic equation,

z3 = 0.64 2 = 0

The system

A

in stable

B

is marginally stable

C

is unstable

D

stability cannot be assessed

Question 66

Identify the circuit show

A

Half wave rectifier

B

Full wave bridge rectifier

C

Center-tapped full wave rectifier

D

Buck Circuit

Question 67

DC average current of a centre tapped full wave rectifier is:

A

2Im/π

B

Im/π

C

Im/2π

D

√2Im/π

Question 68

Which of these is incorrect for an operational amplifier?

A

It has a high voltage gain

B

It is a direct coupled amplifier

C

It was originally designed to perform mathematical operations

D

It is only useful for amplifying AC signals

Question 69

In an ideal op-amp, which is not true?

A

Slew rate is infinite

B

CMRR is zero

C

Input resistance is infinite

D

Open loop voltage gain is infinite

Question 70

In a BJT, if the collector-base junction is forward-biased and the base-emitter junction is forward-biased, which region is the BJT operating in?

A

Saturation region

B

Active region

C

Cutoff region

D

Reverse active region

Question 71

For common emitter configuration, which of the following is the correct relation?

A

Ic < IE

B

Ic = 𝛽 IB

C

Ic = IE

D

Ic = ɑIE

Question 72

What is the circuit in the given diagram called?

A

Half wave rectifier

B

Full wave rectifier

C

Clipper

D

Clamper

Question 73

What are the basic gates in CMOS logic family?

A

AND and OR

B

NAND and NOR

C

AND and NOR

D

NAND and OR

Question 74

What will be the frequency of the output from a JK flip-flop, when J = 1, K = 1, and a clock with pulse waveform is given?

A

Twice the frequency of clock input

B

Independent of the frequency of clock input

C

Half the frequency of clock input

D

Equal to the frequency of clock input

Question 75

Which of the following codes is a sequential code?

A

8421 code

B

2421 code

C

5421 code

D

2441 code

Question 76

Which of these pins will allow to activate and deactivate a multiplexer?

A

Preset pin

B

Logic pin

C

Enable pin

D

Selection pin

Question 77

The decimal equivalent of the octal number (645)8 is:

A

(450)10

B

(451)10

C

(501)10

D

(421)10

Question 78

Ripple counters are also called

A

SSI counters

B

Asynchronous counters

C

Synchronous counters

D

VLSI counters

Question 79

Which of the following plays an important role in improving the device performance of MOSFET?

A

Threshold voltage

B

Dielectric constant

C

Power supply voltage

D

Gate to drain voltage

Question 80

With a 200 kHz clock frequency, eight bits can be serially entered into a shift register in :

A

4 μs

B

40 μs

C

400 μs

D

4 ms

Question 81

Resistive switching is normally employed in

A

All circuit breakers

B

Bulk oil breakers

C

Minimum oil breakers

D

Air blast circuit breakers

Question 82

In case of a 3 phase short circuit in a system, the power fed into the system is:

A

mostly reactive

B

mostly active

C

active and reactive equally

D

reactive only

Question 83

Corona losses are minimized:

A

by reducing conductor size

B

by using smooth conductors

C

providing sharp points in line conductors

D

reducing current density in conductors

Question 84

The relay which is most sensitive to power swings (mal-operation) is:

A

mho relay

B

reactance relay

C

impedance relay

D

all relays:

Question 85

The capacitor switching is easily done with:

A

vacuum CB

B

M.O. circuit breaker

C

SF6 circuit breaker

D

air blast CB

Question 86

Which of the following power semiconductor devices is bidirectional?

A

Thyristor

B

Diac

C

BJT

D

IGBT

Question 87

Which of the following power semiconductor devices is a pulse triggered device?

A

BJT

B

MOSFET

C

IGBT

D

Thyristor

Question 88

Which one of the following triggering methods of an SCR is destructive?

A

Forward voltage triggering

B

Temperature triggering

C

Light triggering

D

Gate current triggering

Question 89

For a three phase fully controlled bridge converter with R load, for what firing angle (alfa) the load current becomes discontinuous?

A

ɑ

B

10

C

30

D

60

Question 90

For a three phase 50 Hz full converter, what is the ripple frequency in the output voltage?

A

50 Hz

B

100 Hz

C

300 Hz

D

150 Hz

Question 91

Devimahatmya, otherwise known as Durgasaptasati belongs to :

A

Bhagavatapurana

B

Brahmavaivartapurana

C

Padmapurana

D

Markandeyapurana

Question 92

In which philosophy, who asserts that the 'Absolute' can be realized through knowledge alone; karma and upasana are subsidiary.

A

Advaita Vedanta Philosophy, Sankara

B

Dvaita Vedanta Philosophy, Maddhva

C

Visistadvaita Vedanta Philosophy, Ramanuja

D

Suddhadvaita Vedanta Philosophy, Vallabha

Question 93

Which one of the following is the only famous War Festival of Kerala?

A

Padayani

B

Kappally Kumbham Thira

C

Chittur Konganpada

D

Kalpathy Rathotsavam

Question 94

Who is the present President of Cochin Devaswam Board?

A

Sri V.K. Ayyappan

B

Sri V. Nandakumar

C

Dr. V.K. Vijayan

D

Sri Chengara Surendran

Question 95

The Sukshma Sarira concept related to the pratistha (idol) is based on:

A

Thriguna concept of Sankhyasastra

B

Epistemology of Mimamsasastra

C

Nine fold forms of devotion

D

Aadhara Chakras mentioned in yogic literature

Question 96

Randumoorthi temple was established by:

A

Suresvaracharya

B

Padmapadacharya

C

Bilvamangalaswamikal

D

Hastamalakacharya

Question 97

Prajnanam Brahma' (Consciousness is The Absolute) is a Mahavakya which is occur in :

A

Mandukyopanisad

B

Brhadaranyakopanisad

C

Aitareyopanisad

D

Chandogyopanisad

Question 98

Who is the author of Tantrapaddhati?

A

Bhavatrata

B

Isanasivaguru

C

Vilvamangala

D

Parameswara

Question 99

Who was the Maharajah of Travancore signed the historic Temple Entry Proclamation on November 12, 1936?

A

Marthandavarma

B

Sthanu Ravi Varman

C

Bhaskara Ravi Varman II

D

Chithira Thirunal Balarama Varma

Question 100

Chandanakavu Saraswati Temple is located at:

A

Thirunavaya, Malappuram

B

Paravur, Ernakulam

C

Panachikkadu, Kottayam

D

Elavur, Ernakulam

105/2022 - Assistant Engineer (Electrical) - Guruvayur Devaswom