Question

A potentiometer wire of length 10 m and resistance of 20 is connected to a battery of 4v find out potential across 1mm of length of wire

Answer 1

Answer:

Potential gradient is 0.016v/m therefore for 10m wire potential difference is 0.16

EMF of cell 0.16 therefore pd across resistance R =2-0.16

Current through whole circuit=2÷(20+R)=(2-0.16)÷R

On solving R=230 ohm