Question

The circuit breaker device which can be used in place of a fuse is called
A) CBD
B) MCB
C) MCD
D) CBF

Answer 1

Hint: The solution is quite simple since out of the four terms that are given to us, the term whose full form you are supposed to know is only one, i.e. MCB which is an acronym for Miniature Circuit Breaker, which is a safety device, just like fuse.

Complete step by step answer:
Let us first tell you what the function of fuse and how it works.
Fuse is a basic electrical safety device that is supposed to protect the circuit in which it is installed from an override current, or an over-supply of current which usually fries the circuit as whole and can be really dangerous for electronic appliances and electronic equipment. A fuse is made up of a metal strip or wire with a small cross-section area, which is usually placed between a pair of electrical metal terminals. To make the fuse usable, it needs to be applied in series with the circuit whom we want to protect. Once the current is too much, i.e. overriding the maximum safe current value for a circuit, the heating effect causes the fuse wire element to melt, thus breaking the circuit. Thus, fuse can also be classified as a sacrificial electronic safety device.

If we talk about MCB, which stands for Miniature Circuit Breaker, it is an automatically operated electrical switch which is used to protect electrical circuits from harm caused by overriding current value due to an overload or short circuit. A miniature circuit breaker is a device, which works on the concept of electromagnetism, which carries a complete molded insulating material. The primary function of this device is to switch the circuit. This means to automatically open the circuit, which we want to protect, when the current in the circuit overrides the set safety value. The main benefit is that MCBs can be switched on or off manually without any extra unnecessary procedure. MCBs are time-delay tripping devices, which means that the device functions whenever there is an overload existing for long periods, long enough to endanger the circuit being protected.

Hence, We can see that the correct answer is option (B), i.e. MCB.

Note: MCBs are better than fuse for various reasons, main ones being that firstly, MCBs are more sensitive than fuse, thus are safer than fuse. Other than that, whilst fuse once operated cannot be used again, MCBs can be used again by simply switching them on again.