Basic Electrical theory Electrical MCQs Test

1. Ohm’s Law states that,

 a) I=VR

b) V=IR

c) R=VI

d) All of the above

As per ohm Law Current is directly proportional to Voltage.

Ans.b

2. The SI unit of Current, Voltage, Resistance, Power, Capacitance, Inductance, Frequency

a) Ampere– Current

b) Volts– voltage

c) Ohm– Resistance

d) Farad-Capacitance

e) Henry-Inductance

f) Hertz– Frequency

g) Watt-Power

3. Standard color code for earth wire is

a) Red

b) Black

c) Green/ Yellow

Ans.c

4. Voltage level to the end consumer is

a) 260/460 V

b) 110/240 V

c) 310/350 V

d) 240/415 V 50hz

Ans.d

5. The power consumed over a period of time can be measured by

a) Energy meter

b) Wattmeter

c) Multimeter

d) Galvanometer

Ans.a

6. A multimeter is a device which can measure

a) Resistance

b) Voltage

c) Current

d) All of the above

Ans.d

7. The circuit in which the current through each of the resistor/load or components is the same

a) Parallel circuit

b) Series circuit

c) Open circuit

d) Closed circuit

Ans.b

8. One commercial unit of energy equals

a) 500 watt-sec

b) One watt-hour

c) One kilowatt-hour

d) Ten kilowatt-hour

Ans.c

9. Earthing is necessary to give protection against

a) Electric shock

b) Voltage fluctuation

c) Overloading

d) High temperature of the conductors

Ans.a

10. According to house wiring rules as per ISI specification, the switchboard should be fitted at a height of

a) 0.5 m

b) 1.5 m

c) 2.5 m

d) 3.5 m

Ans.b

11. The tool used for cutting, removing insulation, jointing and twisting the electric wires and cables even on live line is

a) Hammer

b) Nose plier

c) Screwdriver

d) Combination plier

Ans.d

12. As per ISI specification minimum size of earth wire for light circuit is __________ for copper and__________ for aluminum

a) 1 mm2 and 1.5 mm respectively

b) 1.5 mm2 and 1 mm respectively

c) 2 mm2 and 1.5 mm2 respectively

d) 1.5 mm2 and 2 mm2 respectively

Ans.a

13. The fuse rating is usually defined in

a) Ampere

b) Kilowatt

c) VA

d) All of the above

Ans.a

14. Fuse wire should be connected to

a) Phase wire only

b) Neutral wire only

c) Ground wire only

d) Both (b) and (c)

Ans.a

15. The method to interconnect a switch, a fan and a fan regulator to an electric supply is

a) Connecting each of them in parallel to one another

b) Connecting each of them in series to one another

c) Connecting fan and regulator in parallel and switch in series to them

d) Connecting fan and regulator in series and switch in parallel to them

Ans.b

16. The device used for protection from earth leakage current to prevent electric shocks is

a) Fuse

b) Circuit breaker

c) Residual current device

d) All of the above

Ans.c

17. The test done to check the healthiness of the domestic wiring is

a) Polarity test

b) Insulation resistance test

c) Continuity test

d) All of the above

Ans.d

18. In case of short circuit, ____________ current will flow in the circuit

a) Zero

b) Very low

c) Normal

d) Very high current

Ans.d

19. The insulation resistance of an electrical system is measured using an instrument called

a) Clamp on meter

b) Multimeter

c) Megger

d) Wattmeter

Ans.c

20. The most preferred domestic wiring nowadays is

a) Casing and capping wiring

b) Concealed conduit wiring

c) Cleat wiring

d) Batten wiring

Ans.b

21. The cheapest domestic wiring nowadays is

a) Casing and capping wiring

b) Concealed conduit wiring

c) Cleat wiring

d) Batten wiring

Ans.c

22. A __________ is where the electrical supply is distributed from within the building

a) Switch board

b) Distribution board

c) Service lines

d) All of the above

Ans.b

23. A universal motor can work on

a) AC

b) DC

c) AC and DC

d) None of the above

Ans.c

24. The speed of __________ connected motor are high

a) Delta

b) Star

c) Both (a) and (b)

d) None of the above

Ans.a

25. The device that converts chemical energy to electrical energy is known as

a) Battery

b) Motor

c) Generator

d) All of the above

Ans.a

26. The main function of the rectifier is to convert

a) AC supply to DC supply

b) DC supply to AC supply

c) DC supply to DC supply

d) AC supply to AC supply

Ans.a

27.A device used to step up or step down the AC voltage without changing frequency is called……..

a) Inverter

b) Rectifier

c) Transformer

d) Generator

Ans.c

28. A Transformer having more No turns in secondary winding while comparing to Primary winding is called

a) Step down Transformer

b) Current Transformer

c) Voltage Transformer

d) Step Up transformer

Ans.d

29. A device which converts Mechanical Energy to Electrical Energy is called…………

a) Motor

b) Transformer

c) Generator

d) Solar Panel

Ans.c

30. A device which converts Electrical Energy to Mechanical Energy is called………

a) Motor

b) Transformer

c) Generator

d) Solar Panel

Ans.a

31. Light energy is converted to Electrical Energy through……. System.

a) Motor

b) Transformer

c) Generator

d) Solar Panel

Ans.d

32. A device converts DC voltage to AC voltage is called…….

a) Inverter

b) Rectifier

c) Transformer

d) Generator

Ans.a

33. No of Cycles per second is…….

a) Current

b) Voltage

c)  Ampere

d) Frequency

Ans.d

34. How much voltage is needed to produce 2.5A of current through a 200 ohm resistor?

a)   50V

b)  500V

c)  80V

d)  800V

Ans.b

35. A 1000 watts heater is connected to a 240v AC supply. Then the current Drawn by the heater is?

a) 4.006

b) 4.106

c) 4.160

d) 4.166

Ans.d

36. If a 100 Watts bulb ON for 10 hours, then what will be the amount of consumed electricity?

a) 100 Watts per hour

b) 100 Watts

c) 1kWh

d) 1000 Watts

Ans.c

37. If a 50 Watts bulb ON for 10 hours, then what will be the amount of consumed electricity in 3 days?

a) 5 Watts per hour

b) 10 kWh

c) 15Watts

d) 1.5 kWh

Ans.d

38. A bulb of 50W is switched on for 15 hours per day. How much electrical energy is consumed for the one month?

Formula:

Electrical energy consumption ( in kWhr or units ) = Power (in kW) × time (in hours)

Solve your Self and Answer in Comment Section

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