Question

A potentiometer wire of length 5 m is a connected to a battery. For a certain cell having negligible internal resistance, a null point is obtained at 250 cm. If the length of the potentiometer wire is increased by 1 m, where will be the new position of the null point ?

Answer 1

Answer :- 300 cm

Length of wire = 5 m

Increased Length = 5 + 1 = 6 m, So increase in length of 6/5 of old length.

Null Point is $\alpha$ length of Wire

Old Null Point at 250 m, so new null point is :-

6 / 5 x 250 = 300 cm