A 5 cm long fuse wire of resistivity must melt when the current through it exceeds 3 A

PHYSICS · Subjective · CBSE · Physics · Electricity · Electricity

Problem

A 5 cm long fuse wire of resistivity

1.6\times10^{-6}\,\Omega\,\text{m}

must melt when the current through it exceeds 3 A. The wire melts when the power developed per centimetre reaches

0.9\,\text{W cm}^{-1}

. Calculate the maximum diameter of the wire that can be used for this fuse.