Question

A potentiometer wire has a resistance per unit length $0.1\Omega /m$. A cell of e.m.f. 1.5 V balances against 300 cm length of the wire. Find the current through potentiometer wire.

Answer 1

Balance point of potentiometer $=300cm=3m$

Resistance per unit length $=0.1\Omega /m$

Resistance up to balance point $=0.3\Omega$

$E.m.f$ of cell $=1.5V$

current $=\frac{1.5}{0.3}=5A$

We get, current $=5A.$