Question

Two cells of emfs approximately 5 V and 10 V are to be accurately compared using a potentiometer of length 400 cm.

Options

• The battery that runs the potentiometer should have voltage of 8V.

• The battery of potentiometer can have a voltage of 15 V and R adjusted so that the potential drop across the wire slightly exceeds 10 V.

• The first portion of 50 cm of wire itself should have a potential drop of 10 V.

• Potentiometer is usually used for comparing resistances and not voltages.

Answer 1

The battery of potentiometer can have a voltage of 15 V and R adjusted so that the potential drop across the wire slightly exceeds 10 V.