Physics

Problem

The length of a potentiometer wire is 1200 cm and it carries a current of 60 mA. For a cell of emf 5 V and internal resistance of

20 \Omega

, the null point on it is found to be at 1000 cm. The resistance of whole wire is : a.

80 \Omega

120 \Omega

60 \Omega

100 \Omega