Question

What is/are the advantages of MCB over fuses?
(A) its wire melts unlike fuses wire
(B) it automatically turns off to save from excess electricity
(C) it takes less time to break the circuit as compared to fuse while overloading
(D) None of these

Answer 1

Hint: MCB is an electrical device based on trip off and on but fuse is an electrical device that needs complete replacement of fuse wire after failure.

Complete step by step solution:
MCB i.e. miniature circuit breaker is an automatically operated electrical switch designed to protect the electrical appliances and human beings from electrical shocks and faults. MCB is a common safety device.
MCB has several advantages over fuse:

1. MCB is more sensitive to current than fuse. It detects any abnormality in the current flow and automatically switches off the electrical circuit.

2. In case of MCB, the faulty part of the electrical circuit can be easily identified. On one hand, faulty circuit trips to the off position and on the other hand in case of fuse, the complete fuse wire needs to be checked by opening the fuse grip for confirming the faulty part.

3. MCB provides a better interface with the help of a knob than a fuse. In case of fuse, the complete handle needs to be taken care of.

4. It is very simple to resume to supply with MCB. You just need to push the knob of MCB back to the on position but in case of fuse, the entire fuse wire needs to be replaced.

Hence, (B) and (C) are correct.

Note: MCB is a quick response device that can be easily handled without any wear and tear but fuse melts to save the electrical device from excess current therefore, it needs to be replaced.