Question

A fuse in a motor vehicle electrical system has a resistance of 0.05 Ω. It is designed to blow when the power dissipation exceeds 50 W. What is the current rating of the fuse?

Answer 1

Answer: 31,6 A

Explanation: In order to answer this question we have to use the exptression for the power for any electric sysyem which is given by:

P=I*V where I and V are the current and voltage.

This system can operate as maximum at 50 W so by using Ohm law

P= I^2*R in this case R=0.05Ω

The I= (50 /0.05)^1/2= 31.6 A