Electrical Multiple Choice Questions And Answers

Electrical & Electronics

Electrical Multiple Choice Questions And Answers 

Electrical Multiple Choice Questions And Answers on Electrical MCQ questions  on Electrical objectives questions with answer 

 

1.  For testing appliances, the wattage of the test lamp should be

A) very low
B) low
C) high
D) any value

ANSWER= (c) high

 

2. Switching of a lamp in the house produces noise in the radio. This is because switching operation produces

A) arcs across separating contacts
B) mechanical noise of high intensity
C) both mechanical noise and arc between contacts
D) none of the above

ANSWER= (A) arcs across separating contacts

 

3. Sparking occurs when a load is switched off because the circuit has high

A) resistance
B) inductance
C) capacitance
D) impedance

ANSWER= (b) inductance

 

4. Copper wire of certain length and resistance is drawn out to three times its length without change in volume, the new resistance of wire becomes

A) 1/9 times
B) 3 times
C) 9 times
D) unchanged

ANSWER= (C)9 times

 

5. When the resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will

A) decrease
B) increase
C) remain constant
D) none of the above

ANSWER= (B)increase

 

6. A field of force can exist only between

A) two molecules
B) two ions
C) two atoms
D) two metal particles

ANSWER= (B)two ions

 

7. A substance whose molecules consist of dissimilar atoms is called

A)semi-conductor
B) super-conducto
C) compound
D) insulator

ANSWER= (C)compound

 

8. International ohm is defined in terms of the resistance of

A) a column of mercury
B) a cube of carbon
C) a cube of copper
D) the unit length of wire

ANSWER= (A)a column of mercury

 

9. Three identical resistors are first connected in parallel and then in series. The resultant resistance of the first combination to the second will be

A) 9 times
B) 1/9 times
C) 1/3 times
D) 3 times

ANSWER= (B)1/9 times

 

10. Which method can be used for the absolute measurement of resistances?

A) Lorentz method
B) Raleigh method
C) Ohm’s law method
D) Wheatstone bridge method

ANSWER= (D) Wheatstone bridge method

 

11. Three 6 ohm resistors are connected to form a triangle. What is the resistance between any two corners?

A) 3/2 Q
B) 6 Q
C) 4 Q
D) 8/3Q

ANSWER= (C)4 Q

 

12. Ohm’s law does not apply to the system?

A) semi-conductors
B) D.C. circuits
C) small resistors
D) high currents

ANSWER= (A) semi-conductors .

 

13. Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor has a smaller cross-sectional area has a resistance of 40 ohms the resistance of the other conductor will be

A) 160 ohms
B) 80 ohms
C) 20 ohms
D) 10 ohms

ANSWER= (D)10 ohms

 

14. A nichrome wire used as a heater coil has a resistance of 2 £2/m. For a heater of 1 kW at 200 V, the length of wire required will be

A) 80 m
B) 60 m
C) 40 m
D) 20 m

ANSWER= (A) 80 m

 

15. Temperature co-efficient of resistance is expressed in terms of

A) ohms/°C
B) mhos/ohm°C
C) ohms/ohm°C
D) mhos/°C

ANSWER= (C)ohms/ohm°C