Circuit Breakers and Relays MCQ with Answers

1) Which circuit breaker is installed along with wiring circuit against leakage current protection?

Answer is:

ELCB

Explanation:

.

2) Which relay hold their contacts in position after power is cutoff?

Answer is:

Latching relay

3) How the rupturing capacity of circuit breaker is rated?

Answer is:

MVA

Explanation:

Rupturing capacity of a circuit breaker means the maximum power a circuit breaker can interrupt under a fault. It is usually expressed in Mega volt Ampere (MVA) and it is then the product of the rated breaking current in kilo amperes and rated voltage expressed in kilo volts.

4) What is the pick-up voltage in a over voltage relay indicated?

Answer is:

Minimum voltage to start the relay

5) What is the function of Buchholz relay in power transformer?

Answer is:

1) Which circuit breaker is installed along with wiring circuit against leakage current protection?

ELCB

2) Which relay hold their contacts in position after power is cutoff?

Latching relay

3) How the rupturing capacity of circuit breaker is rated?

MVA

4) What is the pick-up voltage in a over voltage relay indicated?

Minimum voltage to start the relay

5) What is the function of Buchholz relay in power transformer?

Over load and short circuit protection