Question

Why high resistance is used in potentiometer?

Answer 1

Potentiometer:

1. The potentiometer is a null deflection type of instrument, which will give you a measurement when the current passing through the galvanometer is zero.
2. To reach the balance point we slide the jockey wire on the resistance wire till the balance point is reached.

Explanation:

1. A galvanometer is a very sensitive and low current device and when a high current is passed through it, it will burn out.
2. To protect the galvanometer from burning we add a high resistance in series with the galvanometer.
3. Initially, there is a high current passing through the galvanometer, high resistance will prevent the high current from passing the galvanometer.
4. As we reach the balance point current through the galvanometer starts decreasing and the high resistance is replaced by a smaller resistance.

That is why high resistance is used in a potentiometer.