What should be the size of the slide wire of the potentiometer to make it to achieve high accuracy?
Right Answer is:
As long as possible
The size of the slide wire of the potentiometer to make it to achieve high accuracy should be as long as possible.
A potentiometer is an instrument designed to measure an unknown voltage by comparing it with a known voltage. This known voltage is supplied by a standard cell or through a reference source. The potentiometer makes use of null or balanced conditions for the purpose of measurement.
The potential difference across the length of the potentiometer wire is directly proportional to its Length (or) when a steady current is passed through a uniform wire, potential drop per unit length or potential gradient is constant.
E ∝ L ⇒ E = φL
Where φ is the potential gradient
So In the case of longer wire, the fall of potential per unit length is small. In other words, the potential gradient is small. The lesser the potential gradient, the more accurate is the potentiometer.