Question

What is the effect on the null deflection length on decreasing the value of potential gradient in the wire of potentiometer?

Hint:

In a potentiometer, decreasing the potential gradient results in a longer null deflection length, as the potential difference per unit length decreases.

Answer 1

Step 1: Understanding Potentiometer.
A potentiometer is a device used to measure the potential difference by comparing it with a known reference voltage. The null deflection length is the length of the wire over which the potential gradient is balanced by the reference voltage.

Step 2: Effect of Decreasing Potential Gradient.
The potential gradient is defined as the potential difference per unit length of the wire. If the potential gradient is decreased, it means that for a given length of wire, the potential difference is smaller. To achieve null deflection, the length of the wire required will increase. Thus, the null deflection length increases when the potential gradient decreases.

Step 3: Conclusion.
Decreasing the potential gradient will increase the null deflection length.