Electrical installation for power circuits - Electrical Engineering (MCQ) questions and answers

1)   What is the input current of a 2 hp single phase motor, 240 V at 70 % efficiency and 0.8 power factor?

a. 6.95 A
b. 10.95 A
c. 13.52 A
d. 17.68 A
Answer  Explanation 

ANSWER: 10.95 A

Explanation:
No explanation is available for this question!


2)   What is the factor of safety used for current ratings in a power installation?

a. 1
b. 1.5
c. 1.75
d. 2
Answer  Explanation 

ANSWER: 2

Explanation:
No explanation is available for this question!


3)   What are the minimum cross sections of conductors that are used for power wiring?

a. 2.5 mm2 and 1.25 mm2 for aluminium and copper conductors respectively.
b. 1.25 mm2 and 2.5 mm2 for aluminium and copper conductors respectively.
c. 1.5 mm2 and 1.25 mm2 for aluminium and copper conductors respectively.
d. 2.5 mm2 and 2.25 mm2 for aluminium and copper conductors respectively.
Answer  Explanation 

ANSWER: 2.5 mm2 and 1.25 mm2 for aluminium and copper conductors respectively.

Explanation:
No explanation is available for this question!


4)   How many earth connections are required for the motor frame as per the IE rule 61?

a. One
b. Two separate and distinct
c. Three separate and distinct
d. All of these
e. None of these
Answer  Explanation 

ANSWER: Two separate and distinct

Explanation:
No explanation is available for this question!


5)   Which starter is used for slip ring induction motors of high ratings?

a. DOL starter
b. Rotor resistance starter
c. Autotransformer starter
d. All of these
e. None of these
Answer  Explanation 

ANSWER: Rotor resistance starter

Explanation:
No explanation is available for this question!


6)   What is the size of the cable made up of copper conductors used for a 10 hp 500 V DC motor?

a. 7 / 0.915 mm
b. 1 / 2.8 mm
c. 3 / 0.915 mm
d. Both (b) & (c)
e. All of these
Answer  Explanation 

ANSWER: 7 / 0.915 mm

Explanation:
No explanation is available for this question!


7)   What is the maximum length of the flexible conduit in motor installation?

a. Less than 1.25 m
b. Less than 2.25 m
c. Less than 3.5 m
d. Can exceed not more than 5 m.
Answer  Explanation 

ANSWER: Less than 1.25 m

Explanation:
No explanation is available for this question!


8)   Which statement is true, with respect to the motor installation?

a. Wood work is used for mounting switchgears.
b. All equipments used in power wiring shall be of iron clad.
c. Looping of conductors is usually made.
d. The length of flexible conduit is more than 3 m.
Answer  Explanation 

ANSWER: All equipments used in power wiring shall be of iron clad.

Explanation:
No explanation is available for this question!


9)   What is the maximum load that is permitted in a power circuit?

a. 5000 watts
b. 3000 watts
c. 2000 watts
d. 10000 watts
Answer  Explanation 

ANSWER: 3000 watts

Explanation:
No explanation is available for this question!


10)   How many outlets are permitted in a power circuit?

a. 10 points
b. 5 points
c. 2 points
d. 1 point
Answer  Explanation 

ANSWER: 2 points

Explanation:
No explanation is available for this question!