# SSC JE Electrical Important MCQ Part 8

SSC JE Electrical Important MCQ PDF Part 8

1.________ extinguishers are ideal for places with a lot of electrical equipment such as offices or server rooms.

A) N2S

B) Cl2

C) SO2

D) CO2

2.What is the average life of a fluorescent tube

A) 2000 hours

B) 7000 hours

C) 1000 hours

D) 3000 hours

Answer  : B (Fluorescent light bulbs typically have a rated lifespan of 7,000 to 15,000 hours)

3.An ON-OFF switch with overload protection is called a _______.

A) Reversing starter

B) Magnetic starter

C) Manual starter

D) Combination starter

Answer  : C (Manual motor starters are electro-mechanical protection devices for the main circuit. They are used mainly to switch motors manually ON/OFF and protect them fuse less against short-circuit, overload and phase failures. )

4.When checked with an ohm meter an open resistor reads

A) High but within tolerance

B) Zero

C) Infinite

D) Low but not zero

5.The winding of interpoles is connected ________ with the armature.

A) Half in series and half in parallel

B) Both in series and parallel

C) In parallel

D) In series

6.The EMF induced in a coil due to the change of its own flux linked with it is called

A) Dynamically induced EMF

B) Self induced EMF

C) Mutually induced EMF

D) Statically induced EMF

7.In an alternator, the _______ current is generated in the stationary stator.

A) DC

B) Both AC and DC

C) Pulsating DC

D) AC

Answer  : D (The rotating magnetic field induces an AC voltage in the stator windings)

8.The speed with which the turbo alternators operate are

A) 3000 RPM

B) 5000 RPM

C) 1000 RPM

D) 1500 RPM

Answer  : A (The normal speed of a turbo generator is 1500 or 3000 rpm with four or two poles at 50 Hz (1800 or 3600 rpm with four or two poles at 60 Hz))

9.Two bulbs of 500 W and 200 W rated at 250 V will have resistance ratio as
A) 2 : 3

B) 2 : 5

C) 3 : 2

D) 5 : 2

Answer  : B (Resistance of bulb 500 watt R₁=(220)²/500Ω,Resistance of bulb 200 watt R₂=(220)²/200Ω So R₁/R₂=2/5)

10.A quantity whose magnitude has a definite repeating time cycle is called a

B) Transient state periodic

D) Transient

11.________ system is universally adopted for a generation, transmission and distribution of electric power.

A) Two phase

B) Single phase

C) Both single and two phase

D) Three phase

12.Resonant Grounding is also known as

A) Solid earthing

B) Arc suppression coil earthing

C) Reactance earthing

D) Resistance earthing

13.RMS value is defined based on which of the following

A) Charge transfer

B) Voltage

C) Current

D) Heating effect

Answer  : D (Rms (Root mean square) value is defined based on heating effect of wave-forms)

14.In a permanent magnet moving coil instrument, the deflecting torque is directly proportional to

A) Current passing through coil

B) Flux density in air gap

C) Number of turns of coil

D) All of these

Answer  : D (Td = NBldI where N is number of turns,B is magnetic flux density in air gap,l is the length of moving coil,d is the width of the moving coil,I is the electric current)

15.Which of the following effects is used in Wattmeter

A) Chemical effect

B) Electrostatic effect

C) Electrodynamic effect

D) Thermal effect

16.When an electric device, appliance or electrical installation is connected to the earth electrode without a fuse, circuit breaker or resistance/Impedance, It is called ___________.

A) Solidly earthed

B) Earth resistance

D) Earth continuity conductor

17.According to Kirchhoff’s current law, the algebraic sum of current leaving a node in a lumped parameter circuit is equal to

A) Value of voltage drop in the circuit

B) Infinite

C) Unity

D) Zero

18.The measurement errors mainly caused by human mistakes are called

A) Gross error

B) Systematic error

C) Instrumental error

D) Observational error

19.Before starting electroplating, what action is to be necessarily taken

A) Buffing

B) Soldering

C) Cleaning

D) Polishing

20.In which of the following transmission lines is capacitance effect negligible

A) Both long transmission lines and short transmission lines

B) Short transmission lines

C) Long transmission lines

D) Medium transmission lines