Problem

The wire of potentiometer has resistance

4 \Omega

and length 1 m. It is connected to a cell of emf 2 volt and internal resistance

1 \Omega

. If a cell of emf 1.2 volt is balanced by it, the balancing length will be (a) 90 cm (b) 60 cm (c) 50 cm (d) 75 cm