Question

The emf of a standard cell is 1.5V and is balanced by a length of 300 cm of a potentiometer with 10 m long wire. Find the percentage error in a voltmeter which balances at 350 cm when its reading is 1.8 V.​

Answer 1

Answer:3.05

Explanation:

Given,

Balencing point l1​=32cm  when votage applied V=1.5

Balencing point l2​=65cm

Potential gradiant K=xV​=321.5​

potential diffrence in length l2​=K×l2​=V′

V′=321.5​×65=3.05 Volt