Question

A fuse wire melts at 5A. If it is desired that the fuse wire of the same material melt at 10A, then should the new fuse wire be of smaller or larger radius than the earlier one? Give reasons for your answer.

Answer 1

Answer:

Larger radius

Answer 2

The wire of the new fuse should be of a larger radius.

• The new fuse wire should be of a larger radius because current is inversely proportional to resistance ( I ∝ 1/R). This means when the flow of the current increases, resistance in the wire decreases.
• The above explanation is given because resistance is inversely proportional to area which means when the area of the material is increases there is an increase in radius as area = π$r^2$ ( where "r" is the radius) due to which the resistance in the wire decreases leading to more electron flow of in the wire which increases the conductivity.