Electrician in KSFDC, Tourism, Agriculture Answer key

Question 1

What is the rating factor of cable provided with coarse excess current protection?

A

1.14

B

1.23

C

0.81

D

0.787

Question 2

Which type of solder is used for soldering aluminum conductors?

A

Sal ammonia rosin

B

Ker-al-lite

C

Zinc chloride

D

Tallow

Question 3

How many electrons are there in the third cell of the copper atom?

A

18

B

32

C

2

D

8

Question 4

What is the value of electrical conductivity of aluminium conductor?

A

56 mho/meter

B

81 mho/meter

C

61 mho/meter

D

35 mho/meter

Question 5

Which test is conducted to locate the faults in U.G cables?

A

Short circuit test

B

External growler test

C

Insulation resistance test

D

Loop test

Question 6

Which one defines the change in resistance in Ohm (Ω) per degree centigrade (°C)?

A

Temperature co-efficient

B

Laws of resistance

C

Laws of temperature

D

Joules law

Question 7

In the case of electrolytes a rise in temperature causes :

A

no change in resistance

B

increase in resistance

C

decrease in resistance

D

none of the above

Question 8

Calculate the hot resistance of 200W / 250V rated lamp :

A

31.25 Ω

B

312.5 Ω

C

62.5 Ω

D

625 Ω

Question 9

The output voltage of an ideal voltage source is :

A

zero

B

constant

C

dependent on load resistance

D

dependent on internal resistance

Question 10

A semiconductor has generally ———————— Valance electrons.

A

6

B

3

C

2

D

4

Question 11

Which method can be used for measuring low and medium value of resistance?

A

Substitution method

B

Kelvin bridge method

C

Voltmeter and ammeter method

D

Wheat stone bridge method

Question 12

The S.I. unit of specific resistance is :

A

ohm-meter

B

ohm / cm

C

ohm / meter

D

micro ohm / cm^2

Question 13

According to Kirchhoff’s law, the algebraic sign of an ‘IR’ drop is primarily dependent upon the :

A

amount of current flowing it

B

direction of current flow

C

value of resistance

D

battery connection

Question 14

What is the value of resistance in an open circuit?

A

Zero

B

Low

C

Infinity

D

High

Question 15

What is the unit of Reluctance?

A

Weber / metre^2

B

Weber / meter

C

Ampere turns / metre^2

D

Ampere turns / Weber

Question 16

Which is the cause for changing the Permeability?

A

Flux density

B

Magneto motive force

C

Field intensity

D

Reluctance

Question 17

A substance that has a high retentiveness can be used for the manufacture of :

A

Electromagnet

B

Permanent magnet

C

Temporary magnet

D

Paramagnets

Question 18

Which is the diamagnetic substance?

A

Water

B

Air

C

Steel

D

Platinum

Question 19

The direction of induced e.m.f. can be found with the help of :

A

Lenz’s law

B

Flemings left hand rule

C

Right hand palm rule

D

Cork screw rule

Question 20

One Weber/second is called :

A

1 Ohm

B

1 Watt

C

1 Volt

D

1 Ampere

Question 21

The magnetizing force required to wipe off residual magnetism is known as :

A

Retentive force

B

Eddy current loss

C

Coercive force

D

Relative force

Question 22

The example of natural magnet is :

A

ALNICO

B

Electro magnet

C

Nickel – iron

D

Lode-stone

Question 23

Which electrical quantity is directly proportional to the eddy current?

A

Current

B

Frequency

C

Voltage

D

Resistance

Question 24

How the value of capacitance can be decreased?

A

Increasing the distance between the plates

B

Increasing the plate area

C

Increasing the resistance of the plate

D

Using high dielectric constant material

Question 25

Which of the following quantity maintain the same polarity during charging and discharging of a capacitor?

A

Resistive drop

B

Charge of capacitor

C

Capacitor Current

D

Capacitor voltage

Question 26

What is the unit of susceptance?

A

Ohm

B

Weber

C

Mho

D

Henry

Question 27

What is the formula to find 3 phase Reactive power (Pr) if the line voltage is ‘V_L’ and line current is ‘I_L’?

A

Pr = √3 VL IL Sinθ

B

Pr = √3 VL IL Cosθ

C

Pr = 3 VL IL Cosθ

D

Pr = VL IL Sinθ

Question 28

What is the main cause for below 0.5 lagging power factor in 3 phase system?

A

Fluctuation of voltage

B

Reactive power due to more inductive load

C

Reactive power due to more capacitive load

D

True power due to resistive load

Question 29

A 3-phase, 4 wire, 230/415 volt system is supplying lamp load at 230 volt. If a 3-phase motor is now switched ON across the same supply, then :

A

neutral current will increase

B

whole line current will decrease

C

neutral current remain unchanged

D

power factor will be improved

Question 30

For plate earthing, plate electrodes thickness when made of G.I or steel should not be less than :

A

1.3 mm

B

2.15 mm

C

6.3 mm

D

3.15 mm

Question 31

According to IE rule the leakage current in an installation should not exceed one ———————— th part of the maximum current supplied to the installation.

A

500

B

100

C

5000

D

1000

Question 32

The size of the earth continuity conductor in a circuit should be based up on the :

A

Voltage of the system

B

Size of largest service conductor

C

Size of smallest service conductor

D

Leakage current in the system

Question 33

In surface conduit wiring, saddles should be fitted at intervals of not more than ———————— meter.

A

0.5

B

1.5

C

0.75

D

1

Question 34

In batten wiring, Link clips will have two holes for :

A

50 mm

B

40 mm

C

30 mm

D

20 mm

Question 35

According to IE rule, the measured insulation resistance should not be less than :

A

1 ohm

B

1 kilo ohm

C

1 mega ohm

D

10 mega ohm

Question 36

Eight carbon – zinc cells in series have an output of ———————— volt.

A

1.5

B

12

C

16

D

8

Question 37

What is the out voltage of lithium cell?

A

1.2 volt

B

1.5 volt

C

1.8 volt

D

2.5 volt

Question 38

Which cell is most often used in digital watches?

A

Mercury cell

B

Carbon – zinc cell

C

Voltaic cell

D

Alkaline cell

Question 39

Which is used as an electrolyte in lead acid battery?

A

Potassium hydroxide

B

Dilute sulfuric acid

C

Ammonium chloride

D

Hydrochloric acid

Question 40

What is the effect of buckling defect in lead acid battery?

A

Reducing the strength of electrolyte

B

Increasing the internal resistance

C

Making short between the electrolytes

D

Bending of the electrodes

Question 41

The DC Generator works on the principle of :

A

Faraday’s law

B

Joules law

C

Coulomb’s law

D

Lenz’s law

Question 42

Which type of DC machine poles is residual magnetism necessary?

A

Motor

B

Separately excited generator

C

Shunt motor

D

Permanent magnetic type generator

Question 43

Which type of motor that does not have a commutators?

A

DC Shunt

B

AC Series

C

Repulsion motor

D

Induction motor

Question 44

The lowest starting torque of the motor :

A

Universal motor

B

Shaded Dole motor

C

Capacitor start capacitor run motor

D

Repulsion Motor

Question 45

Hydroelectric power station located :

A

Desert area

B

Swamps

C

Hilly area

D

Grass land

Question 46

The full form of XLPE cable is :

A

cross linked polyethylene cable

B

cross line poly ethylene cable

C

cross lead paper ethylene cable

D

cross linked paper ethylene cable

Question 47

Wave winding has ———————— parallel path.

A

four

B

two

C

one

D

equal No. of poles

Question 48

In permanent capacitor motor the direction is revised by inter change the :

A

Centrifugal switch terminal

B

Supply terminal

C

Capacitor terminal

D

Auxiliary winding terminal

Question 49

In stay wire ———————— type of insulator are used.

A

egg type

B

pin type

C

shackle type

D

suspension type

Question 50

Surge tank is used in to function of :

A

supply water in penstock

B

produce surge in the pipe line

C

avoid water hammering in pen stock

D

none of the above

Question 51

Transformer working on the principal of :

A

static induction

B

self induction

C

dynamic induction

D

mutual induction

Question 52

In normal case inter poles are connected in :

A

parallel with the field winding

B

series to the load

C

series with the field winding

D

parallel to the load

Question 53

While testing a capacitor with a multi meter the needle shows zero position right from the beginning indicator to the capacitor is :

A

open circuit

B

in good condition

C

start circuit

D

change in capacity

Question 54

Transformers are rated in :

A

KW

B

KWH

C

KVR

D

KVA

Question 55

In nuclear power section graphite is used for :

A

moderator

B

fuel

C

coolant

D

electrode

Question 56

In armature core lamination is to reduce :

A

Copper loss

B

Eddy current loss

C

Hysteresis loss

D

Wintage loss

Question 57

In slip induction motor has :

A

short circuited rotor

B

double cage rotor

C

wound rotor

D

none of the above

Question 58

Two transformer operated in parallel will share the load depending upon their :

A

per unit impendence

B

efficiency

C

rating of KVA

D

leakage reactance

Question 59

For low discharge and high load water turbine using in :

A

Kaplan

B

Pelton wheel

C

Francis

D

Propeller

Question 60

In DC generator the emf equation is :

A

E = ΦZN/60 x A/P Volt

B

E = ΦZP/60 Volt

C

E = ΦZN/120 Volt

D

E = ΦZN/60 x P/A Volt

Question 61

Thermal over load relay is provided in a starter to protect the motor against :

A

short circuit

B

excess current

C

open circuit

D

low voltage

Question 62

Solar cell are made of :

A

Aluminum

B

Germanium

C

Silicon

D

Cadmium

Question 63

Corona is accompanied by :

A

Violet visible discharge in the darkness

B

Hissing sound and power

C

Vibration and radio interference

D

All of the above

Question 64

The solar cell convert in :

A

Solar energy into electrical energy

B

Solar energy into thermal energy

C

Thermal energy into electrical energy

D

Chemical energy into electrical energy

Question 65

In welding purpose which type of DC generator is used :

A

DC shunt generator

B

DC series generator

C

DC differential compound generator

D

DC cummulate compound generator

Question 66

The running speed of a 3-phase squirrel cage induction motor is :

A

The synchronous speed

B

Less than the synchronous speed

C

More than the synchronous speed

D

Double the synchronous speed

Question 67

In nuclear reactor usually function :

A

fission

B

fusion

C

both fission and fusion

D

none of the above

Question 68

Which supply source changes the polarity constantly?

A

DC supply

B

Dynamic

C

Battery

D

AC supply

Question 69

The counter e.m.f. oppose :

A

Current

B

Applied voltage

C

Torque

D

Thermal voltage

Question 70

According to NE code the colour code for the neutral :

A

Red

B

Blue

C

Black

D

Green

Question 71

In thermal nuclear reactors for power generation which type of fuel is used :

A

U^238

B

Th^232

C

Pu^239

D

U^235

Question 72

Direct current is essential for the function of :

A

Arc lamp

B

Mercury Vapor lamp

C

Sodium Vapor lamp

D

Fluorescent lamp

Question 73

In electric traction which type of motor is used?

A

DC shunt

B

DC compound

C

DC long shunt compound

D

DC series

Question 74

During continuity test in an installation the mugger indicated reading in :

A

one mega ohm

B

zero mega ohm

C

500 mega ohm

D

infinity mega ohm

Question 75

Biogas consists :

A

Methane and carbon dioxide with some impurities

B

Only Methane

C

A special Organic Gas

D

Only Ethane

Question 76

By using the device AC power can convert DC power :

A

Generator

B

Alternator

C

Rectifier

D

Transformer

Question 77

At no load the speed of a DC series motor is :

A

normal

B

zero

C

infinity

D

3600 rpm

Question 78

NVC used in a starter to protected the motor against :

A

short circuit

B

open circuit

C

excess current

D

low voltage

Question 79

The tridal power plant turbine usually employed in :

A

Reaction type

B

Reversible type

C

Propeller type

D

Simple impulse type

Question 80

The back e.m.f. of a DC motor depends on the :

A

field flux

B

shape of the conductor

C

type of commutator

D

brush material

Question 81

The closeness of the measured value of a quantity, by an instrument, to its true value is known as :

A

Error

B

Accuracy

C

Resolution

D

Precision

Question 82

The basic movement in a permanent magnet moving coil instrument is called as :

A

Faraday movement

B

Lenz’s movement

C

d’Arsonval movement

D

d’Alexandre movement

Question 83

Consider a coil having an area of ‘A’ and with ‘N’ number of turns be placed between the poles of a permanent magnet. Let ‘I’ be the current flowing in the coil producing a magnetic flux density of ‘B’. Then the resulting deflecting torque ‘T_d’ exerted on the coil will be :

A

Td = NBAI

B

Td = (NBI)/A

C

Td = N2BAI

D

Td = NBI^2

Question 84

Constant uniform deviation of operation of an instrument due to the instrument itself, observation of the observer or environmental conditions, resulting in errors when taking a measurement is called :

A

Gross errors

B

Random errors

C

Absolute errors

D

Systematic errors

Question 85

The opposing force that brings the pointer in an indicating instrument to its final deflected position by avoiding oscillations is :

A

Deflecting torque

B

Damping torque

C

Controlling torque

D

Indicating torque

Question 86

A transformer is a static device that is used to :
(i) convert voltage to a higher (step-up) or lower (step down) level
(ii) convert current to a higher (step-up) or lower (step down) level
(iii) convert frequency to a higher (step-up) or lower (step down) level

A

both (i) and (ii)

B

both (i) and (iii)

C

both (ii) and (iii)

D

all (i), (ii) and (iii)

Question 87

An ideal transformer has 900 turns and 90 turns in its primary and secondary windings respectively. If 220 V, 50 Hz AC is applied at its primary, What will be the AC available at its secondary?

A

22 V, 5 HZ AC

B

2.2 KV, 50 HZ AC

C

22 V, 50 HZ AC

D

2.2 KV, 500 HZ AC

Question 88

When connecting two or more transformers in parallel, a dead short circuit will be produced in the secondary, if :

A

the voltage ratio of the primaries and secondaries are not identical

B

the transformers are not properly connected with regard to the polarity of primary and secondary terminals

C

the percentage impedance of the transformers are not equal in magnitude

D

the kVA ratings of the transformers are different

Question 89

The core of a transformer is laminated to reduce :

A

Hysterisis losses

B

Copper losses

C

Saturation losses

D

Eddy current losses

Question 90

The primary and secondary voltages of an auto transformer are 600 V and 300 V respectively. If the secondary current is 90 A, then the primary current is :

A

70 A

B

30 A

C

45 A

D

100 A

Question 91

A forward biased Silicon diode, will start to conduct when the applied voltage across it reaches :

A

0.7 V

B

0.3 V

C

1.7 V

D

1.3 V

Question 92

If a source of light emits light equally in all directions, then the Illuminance at any point on a plane perpendicular to the line joining the point and the source is :

A

directly proportional to the square of the distance between the source and the plane

B

inversely proportional to the square of the distance between the source and the plane

C

directly proportional to the distance between the source and the plane

D

inversely proportional to the distance between the source and the plane

Question 93

The type of lamp in which gas or vapour is made luminous by an electric discharge through them is :

A

Halogen lamp

B

Incandescent lamp

C

LED lamp

D

Discharge lamp

Question 94

If, for a bipolar junction transistor, α = 0.99 , then β = :

A

0.099

B

1

C

99

D

100

Question 95

Reverse breakdown of a PN diode under reverse bias due to increase in kinetic energy of free electrons is called :

A

Zener breakdown

B

Avalanche breakdown

C

Tunnel breakdown

D

Schottky breakdown

Question 96

The majority charge carriers in P type semiconductor are :

A

positive ions

B

electrons

C

negative ions

D

holes

Question 97

When a group V element such as arsenic is added to pure silicon, it results in the type semiconductor referred to as :

A

acceptor type

B

donor type

C

intrinsic type

D

none of the above

Question 98

The type of diode that exhibits negative resistance under low forward bias condition is :

A

Varactor diode

B

Zener diode

C

Schottky diode

D

Tunnel diode

Question 99

When compared to fullwave rectifier, a half wave rectifier is characterised by :

A

excessive ripple, small value of rectification efficiency, small value of transformer utilization factor and DC saturation of transformer core

B

excessive ripple, high value of rectification efficiency, high value of transformer utilization factor and DC saturation of transformer core

C

lower ripple, small value of rectification efficiency, high value of transformer utilization factor and DC saturation of transformer core

D

lower ripple, high value of rectification efficiency, small value of transformer utilization factor and DC saturation of transformer core

Question 100

For a bipolar junction transistor to operate in the active region, its :

A

collector-emitter junction is forward biased and base-collector junction is reverse biased

B

base-collector junction is forward and base-emitter junction is reverse biased

C

base-emitter junction is forward biased and base-collector junction is reverse biased

D

collector-emitter junction is reverse biased and base-collector junction is forward biased

121/2021 - Electrician - KSFDC, Tourism, Agriculture