Question

Length and resistance of a potentiometer wire are 4 m and 1022 respectively. It
is connected to a cell of emf 2 volt. Another cell when joined to this potentiometer
and null point is measured at 250 cm. Find out the emf of the second cell.​

Answer 1

Answer:

Correct option is

A

0.75 V/m

Current, I=E/R=3/10

Potential across the potentiometer wire is: V

p

=10I=3V

Potential gradient is: k=

l

V

p

=3/4=0.75 V/m