Question

Fuse wire is a wire of
(A) High resistance and high melting point
(B) High resistance and low melting point
(C) Low resistance and low melting point
(D) Low resistance and high melting point

Answer 1

Hint:Here, you are asked the properties of a fuse wire. In order to answer this question, you need to consider the role of fuse wire in the area of electricity. After picturing out what a fuse wire is used for, you can determine the type of wire as per the role performed by the fuse wire.

Complete answer:
Fuse is a device used for safety purposes. A fuse functions in order to provide protection to an electrical circuit from the overcurrent. There are different types of fuses available and depending on the applications, various fuses are used according to their specific current and voltage ratings, response times and the capacity of breaking.

Wiring regulations give the maximum value of current that is needed to be supplied through that circuit and obviously the current that is needed to be passed through the fuse. For faulty systems, fuse is an automatic means of blocking the current.

A fuse contains a strip of metal or a metal wire having a small cross section area. It was discussed that fuse is used for protection of a circuit from overcurrent. Whenever there is a passage of high amount of current, the fuse breaks the circuit by melting itself.

For this to happen, the melting point of wire is kept low. As a high amount of current is passing, resistances of the fuse wire have to be large due to which the heat produced will be high and it is broken down immediately.Hence, fuse wire is a wire of high resistance and low melting point.

Hence, option B is correct.

Note: Here, we have discussed in detail about fuse. The problem was protecting the electrical appliances or the electrical circuit from passage of high amounts of current. The fuse due to its high resistance and low melting point, enhances the production of heat and melts down in order to block further passage of current.