AB is a potentiometer wire (Fig 3.4). If the value of R is increased, in which direction will the balance point J shift?

Question

Philoid · Accepted Answer

As the resistance R increases, current I through the circuit decreases.

This decreases the potential difference across the potentiometer which results in decrease in the potential gradient k across AB.

At balance point,

As k decreases, length l increases for a constant emf E.

Hence, the balance point moves towards B.