K.S.E.B Sub Engineer (Electrical) Question Paper

Question 1

Temperature regulating component on an automatic iron is.............

A

Heating element

B

Pressure plate

C

Sole plate

D

Thermostat

Question 2

Internal growler is used to test the ............

A

Rotor winding

B

Stator winding

C

Bearing

D

Starter connection

Question 3

The resistance of starting winding in single-phase motor is .................

A

Less than running

B

Same as the other

C

More than running

D

More or less than running

Question 4

Rotor of a normal repulsion motor is similar to that of ...........

A

Squirrel cage motor

B

Shaded pole motor

C

Slip-ring induction motor

D

DC motor

Question 5

The purpose of capacitor in ceiling fan is ............

A

Give phase shift

B

Control the speed

C

Increase the speed

D

Improve power factor

Question 6

Mica falls in .............. insulation

A

Class A

B

Class B

C

Class C

D

Class Y

Question 7

Shaded pole motor is used for ..............

A

Compressors

B

Printing press

C

Lathes

D

Small fan

Question 8

Neon sign tubes can be used for ............. purpose

A

Advertising

B

Search light

C

Street light

D

Domestic lighting

Question 9

Sodium vapour lamp gives ........... colour.

A

Bluish

B

Reddish

C

Yellowish

D

Pink

Question 10

A lead acid cell should not be discharged below .................. volt.

A

2.3 volt

B

1.8 volt

C

2 volt

D

2.15 volt

Question 11

The rotating part of a ceiling fan is .............

A

Starting and running winding

B

Squirrel cage winding

C

Squirrel cage winding and the body

D

Running winding only

Question 12

The capacitor in a ceiling fan is connected in .................

A

Series with the starting winding

B

In parallel to the starting winding

C

In series to the running winding

D

In series to the starting and running

Question 13

In a shaded pole motor the revolving field is produced by .............

A

Capacitor

B

Regulator

C

Winding

D

Shading ring

Question 14

The choke coil of an operating tube is short-circuited. What is the consequence?

A

Lamp become off

B

Lamp becomes less bright

C

Over current flows and damage the lamp

D

No effect is visible

Question 15

What is the advantage of twin tube connection?

A

Less power is consumed

B

Stroboscopic effect is eliminated

C

More light than single tube

D

Efficiency can be increased

Question 16

Which of the following is not a good conductor?

A

Aluminium

B

Copper

C

Silver

D

Porcelain

Question 17

Transformer ratings are usually expressed in terms of ............

A

Volt ampere

B

Volt

C

Ampere

D

Watts

Question 18

Potential difference that causes the breakdown of insulation is called as ................

A

Brake down voltage

B

Dielectric strength

C

Insulating resistance

D

Ampere capacity

Question 19

Soldering is done on joints to improve the ...............

A

Tensile strength

B

Resistivity

C

Ductility

D

Conductivity

Question 20

The maximum light points allowed in one circuit is .............

A

20 Nos

B

15 Nos

C

10 Nos

D

Any No

Question 21

If the winding has group of coils having the same centre it is known as

A

Concentric winding

B

Concentrated winding

C

Distributed winding

D

Skin Winding

Question 22

The distance between clips in horizontal runs should not be more than ............. cm.

A

25 cm.

B

15 cm.

C

20 cm.

D

10 cm.

Question 23

In order to prevent creeping energy meter ............. is provided.

A

Disc is made of aluminium

B

Brake magnet is used

C

Diametrically opposite holes are drilled in the side

D

Shading bands are used

Question 24

If power factor of a circuit is unity, its reactive power is ...............

A

Zero

B

Unity

C

Maximum

D

Minimum

Question 25

kWh meter can be classified as a /an ................ instrument.

A

Deflecting

B

Integrating

C

Digital

D

Recording

Question 26

Potential transformer is used for connecting .............

A

Energy meter to height current line

B

Voltmeter to primary side

C

Voltmeter to high voltage line

D

Current coil to low voltage line.

Question 27

............... motor is used for electric traction.

A

DC series motor

B

DC shunt motor

C

DC compound motor

D

Stepper motor

Question 28

A staircase point is operated with ............ switch.

A

Two one-way switch

B

Two intermediate switch

C

Three one-way switch

D

Two two-way switch

Question 29

The earth conductor provides a path to ground for ................

A

Over current

B

Leakage current

C

High Voltage

D

Circuit current

Question 30

Fuse operate due to the ............... effect electric current.

A

Magnetic

B

Electrostatic

C

Heating

D

Chemical

Question 31

The process by which an e.m.f. is induced in a DC generator is called

A

Dynamic

B

Static

C

Chemical

D

Thermal

Question 32

DC supply is used for the operation of ..............

A

Mercury vapour lamp

B

Sodium vapour lamp

C

Fluorescent lamp

D

Arc lamp

Question 33

Speed of a synchronous motor ............

A

Reduces as load increases

B

Remains constant

C

Increase as load increase

D

Is an in induction motor

Question 34

Synchronous motor can operate at .............. pF.

A

Lagging power factor only

B

Unity power factor only

C

Leading power factor

D

Lagging and unity power factor

Question 35

If a single-phase motor runs slow, the cause may be:

A

Overload

B

Low frequency

C

Low voltage

D

Any of the above

Question 36

Alternators are rated in ..........

A

kVA

B

kw

C

HP

D

KVAR

Question 37

The disadvantage of shaded pole motor ..........

A

Low starting torque

B

Low efficiency

C

Very little overload capacity

D

All of the above

Question 38

A DC generator works on the principle of ...............

A

Flemings right-hand rule

B

Farady's law of electromagnetic induction

C

Lenz's law

D

Farday's laws of electrolysis

Question 39

The material used for split ring in a DC machine is .................

A

Iron

B

Silver

C

Aluminium

D

Copper

Question 40

In small DC machine the yoke is made up of ...............

A

Cast-iron

B

Brass

C

Aluminium

D

Copper

Question 41

In a ................ generator the voltage can be build up even if there is no residual magnetism.

A

Series generator

B

Separately excited generator

C

Compound generator

D

Shunt generator

Question 42

The main flux in a generator distorts due to the ................

A

Resistance in the load

B

Current in the commutator

C

Current in the armature conductor

D

Current in the field coil

Question 43

Which single-phase motor has relative high power factor?

A

Universal motor

B

Split phase motor

C

Repulsion motor

D

Synchronous motor

Question 44

How many slip-rings will be there in a 3-phase rotating field type alternator?

A

3 Nos.

B

2 Nos

C

4 Nos

D

It depends on manufacturer

Question 45

Power factor of an alternator is determined by its ..................

A

Speed

B

Excitation

C

Load

D

Prime mover

Question 46

The most reliable methods of synchronising alternator is to use

A

3 lamp dark method

B

3 lamp bright

C

2 bright one dark method

D

A synchroscope

Question 47

The speed of a squirrel cage inductor can be varied by ..............

A

Varying the supply frequency

B

Varying the supply voltage

C

Varying the current drawn

D

Inserting a resistance in the rotor circuit

Question 48

Insulation resistance is measured in ..............

A

In ohms

B

Kilo ohms

C

Kilo volt

D

Megohms

Question 49

A 4 pole, 50 Hz synchronous machine runs at ................ r.p.m.

A

750

B

3,000

C

1,500

D

1,440

Question 50

A bridge rectifier gives ...........

A

A full-wave rectified DC

B

Half-wave rectified DC

C

Full-wave filtered DC

D

Half-wave filtered DC

Question 51

When two capacitors 8 MFD are connected in parallel, the total capacitance is ...........…..….…....

A

4 MFD

B

16 MFD

C

2 MFD

D

1/4 MFD

Question 52

All day efficiency of a transformer is the ratio of the ..............

A

kWh output to the kWh input per day

B

kWh output to kWh input

C

Output power and input power

D

Input power and output power

Question 53

Interpoles in a DC generator are usually wound with:

A

Fine gauge copper winding wire

B

Insulating covered brass conductor

C

Heavy gauge winding wire

D

None of the above

Question 54

A2 kW 200 V, DC generator will supply a load current of ..............

A

2 Amp

B

4 Amp

C

20 Amp

D

10 Amp

Question 55

AC magnets are made of laminated iron to ...............

A

For better induction

B

To reduce eddy current losses

C

For AC and DC use

D

To reduce reluctance

Question 56

The purpose of oil in a transformer is to ...........

A

Lubricate

B

Cool the winding

C

Insulate and cool

D

Reduce eddy current

Question 57

When the motor is standstill in an induction motor the rotor frequency is

A

Equal to the stator frequency

B

Higher than stator frequency

C

Zero

D

Lower than the stator frequency

Question 58

The synchronous speed of an 8 pole induction motor operates at 50 Hz supply is .................

A

3,000 r.p.m.

B

1,000 r.p.m.

C

1,500 r.p.m

D

7,500 r.p.m

Question 59

The directions of rotation of a DC motor is determined by ..............

A

Flemings right-hand rule

B

Flemings left-hand rule

C

Cork screw rule

D

Right-hand grip rule

Question 60

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

A

Shape of the conductor

B

Type of commutator

C

Field flux

D

Brush material

Question 61

A starter is necessary to start a DC motor because ....................

A

Controls the motor speed

B

Limits the starting current

C

Limits the back e.m.f

D

Limits the field current

Question 62

When the load is removed form and induction motor the speed will be:

A

Decrease

B

Remain the same

C

Increases slight

D

Equal to synchronous speed

Question 63

Which motor would you select as a drive for a clock?

A

Single - phase synchronous motor

B

DC series motor

C

Single - phase capacitor start motor

D

Single - phase induction motor

Question 64

Selection of domestic pump set depend upon the .............

A

Quantity of water to be lifted

B

Height of water to be delivered

C

Time required for lifting required quantity of water

D

All of the above

Question 65

A pump may not lift water if there is leakage in ..............

A

Delivery pipe

B

Suction pipe

C

Sump / well

D

Overhead tank

Question 66

Zener diode is operated as ...............

A

Reverse bias mode

B

Forward bias mode

C

Unidirection

D

Under voltage protection

Question 67

Single - phasing preventor is specially designed for .................

A

Over voltage protection

B

No voltage protection

C

Unbalanced voltage protection

D

Under voltage protection

Question 68

For safety the fuses should placed in ................

A

Neutral wire

B

Earth wire

C

Any wire

D

Phase wire

Question 69

ELCBS are specially used to disconnect the supply in ................. condition

A

Ground or earth

B

Short - circuited

C

Open - circuited

D

Overload

Question 70

The frequency of voltage generated by an alternator having 4 poles and running at 1,800 r.p.m is ..............

A

70

B

60

C

50

D

45

Question 71

The current taken by an electric iron of 80 W 240 V is:

A

2 Amp

B

3 Amp

C

4 Amp

D

5 Amp

Question 72

Heat developed in a conductor is proportional to the .............

A

Square of the power

B

Square of the resistance

C

Square of the current

D

Square of the time

Question 73

The total resistance of 45 Ω and 90 Ω in series is ..................

A

135 Ω

B

45 Ω

C

68.7 Ω

D

30 Ω

Question 74

Synchronous motor requires .............

A

AC supply only

B

DC supply only

C

DC supply and permanent magnet

D

AC and DC

Question 75

A material that is slightly repelled by a magnet is called:

A

Magnetic

B

Paramagnetic

C

Diamagnetic

D

Ferromagnetic

Question 76

Resistance of aluminium wire of given length and diameter when compared with that of copper wire is ................

A

Same

B

More irrespective of the size

C

Less irrespective of size

D

Equal for certain specified length

Question 77

If the diameter of given length is doubled, its resistance will .........

A

Be doubled

B

Be halved

C

Remain the same

D

Be 1/4th time

Question 78

Cells are connected in series to ..............

A

Increase the output voltage

B

Decrease the output voltage

C

Decrease the internal resistance

D

Increase the current capacity

Question 79

The collection of hydrogen gas around the positive electrode of a cell is called ............

A

Amalgamation

B

Polarisation

C

Ionisation

D

Oxidation

Question 80

The phase relationship between voltage and current in a pure capacitive circuit is ..............

A

E may lead or lag by 90°

B

E leads I by 90°

C

E and I are in phase

D

E lags I by 90°

Question 81

A lead acid cell is rechargeable because ................

A

Its electrolyte is sulphuric acid

B

It is a wet cell

C

Its reaction is reversible

D

Its electrolyte has high sp.resistance

Question 82

A starter used for slip-ring induction motor is .................

A

Rotor resistance starter

B

DOL starter

C

Star delta starter

D

Automatic star delta

Question 83

A 100 AH battery should deliver a current of a 8 Amp. for approximately ........... hour.

A

100

B

8

C

20

D

12

Question 84

Total capacitance of two 10 MFD capacitors are connected in parallel is ......... MFD

A

5

B

10

C

20

D

100

Question 85

Which of the following relationship is true?

A

cos Φ = True power / Apparent power

B

cos Φ = Apparent power / True power

C

cos Φ = Reactive power / True power

D

cos Φ = True power / Reactive power

Question 86

In a 3-phase alternator the coils have a phase difference of .......... degree

A

240⁰

B

120⁰

C

60⁰

D

360°

Question 87

Power in a 3-phase balance load is ................

A

2 VL IL cosΦ

B

√3 VP IL cosΦ

C

3VP IP cosΦ#

D

3VL IL cosΦ

Question 88

2 wattmeter method of power measurement is applicable in ............. system

A

Balanced as well as unbalanced load

B

Balance load

C

Unbalance load

D

Out of balanced load

Question 89

A permanent magnet M.C. instrument will read ............ quantity.

A

Only AC

B

Both AC and DC

C

Pulsating DC

D

Only DC

Question 90

A gravity controlled instrument will read ............. quantity

A

Vertical

B

Horizontal

C

Inclined

D

Any

Question 91

Which of the following effects is used in a wattmeter?

A

Thermal

B

Electrodynamic

C

Chemical

D

Electrostatic

Question 92

Which of the following instrument cannot be used both AC and DC?

A

Dynamometer type

B

Moving iron type

C

Hot wire type

D

Induction type

Question 93

The maximum current that can pass through 2 Ω 2 watt resistor will be ......... Amp

A

4 Amp

B

3 Amp

C

1 Amp

D

2 Amp

Question 94

Before using an Ohmmeter you must .................

A

Select the range

B

Short the leads

C

Set the zero

D

Do all the above

Question 95

A megger measures resistance in ..............

A

Millions of ohm

B

Ohm

C

Hundreds of ohm

D

Thousands of ohm

Question 96

Potential transformer can be regarded as ............. transformer

A

Small capacity

B

Step up

C

Step down

D

High ratio

Question 97

A tong tester is an instrument having ...............

A

Current transformer

B

Current transformer with an ammeter

C

Potential transformer

D

Miniature transformer

Question 98

In a 3-phase, 4-wire system the neutral current at balanced load is

A

Zero

B

High

C

Low

D

Any value

Question 99

A wattmeter is .................

A

An integrating instrument

B

Recording instrument

C

An indicating instrument

D

An absolute instrument

Question 100

A 3-phase, slip-ring induction motor has ............ rotor.

A

Short - circuited rotor

B

Wound rotor

C

Double cage rotor

D

None of these

103/2005 - Sub Engineer (Electrical) - K.S.E.B