Selection of Circuit Breaker - Electrical Engineering (MCQ) questions and answers

1)   What is the percentage of occurrence of symmetrical faults?

a. 10 %
b. 15 %
c. 5 %
d. None of these
Answer  Explanation 

ANSWER: 5 %

Explanation:
No explanation is available for this question!


2)   What will be the multiplying factor if the speed of the circuit breaker is 2 cycles?

a. 2.2
b. 1.2
c. 2.8
d. 1.4
Answer  Explanation 

ANSWER: 1.4

Explanation:
No explanation is available for this question!


3)   If the speed of the circuit breaker is 8 cycles or slower than that what will be the multiplying factor?

a. 2.3
b. 1.0
c. 1.5
d. 1.7
Answer  Explanation 

ANSWER: 1.0

Explanation:
No explanation is available for this question!


4)   What is the rated breaking capacity of the circuit breaker?

a. The product of rated voltage and rated breaking current
b. The product of rated voltage and rated symmetrical breaking current
c. The product of fault voltage and breaking current
d. None of these
Answer  Explanation 

ANSWER: The product of rated voltage and rated symmetrical breaking current

Explanation:
No explanation is available for this question!


5)   What is the multiplication factor to be multiplied with symmetrical momentary current to account for the presence of DC off set current?

a. 1.2
b. 1.5
c. 1.6
d. 2.5
Answer  Explanation 

ANSWER: 1.6

Explanation:
No explanation is available for this question!