Question

A potentiometer is considered a versatile and accurate device to make an electrical measurement of EMF. Why?

• A. Because the method involves a combination
• B. There are cells involved
• C. Because of potential gradients
• D. As there is no flow of current through the galvanometer

Hint:

A potentiometer measures EMF accurately as no current flows through the cell during null condition.

Answer 1

The Correct Option is D

A potentiometer is used to measure EMF accurately because it works on the principle of null deflection.
When the galvanometer shows zero deflection, it indicates that no current flows through it, ensuring that the EMF of the cell is measured without drawing any current.
This avoids internal resistance effects, making the measurement highly accurate.