A fuse rated at 0.8 A blows when the switch is closed. If an 80 V supply is supplying power to the circuit, what would be the maximum possible value of the resistance for which the current flows through the circuit?

A fuse rated at 0.8 A blows when the switch is closed. If an 80 V supply is supplying power to the circuit, what would be the maximum possible value of the resistance for which the current flows through the circuit?

Detailed Explanation

The fuse is rated at 0.8 A which means that the current will continue flowing through the circuit when the current is limited to 0.8 A. According to ohm's law, \(I = \frac{\mathrm{V} }{\mathrm{R} } \) . First option will give I=80/100=0.8 A which is the rated voltage and the current will flow through the circuit. For second, third and fourth options, currents are I=80/90=0.89, I=80/80=1 A and I=80/70=1.14 A which are greater than the rated current.