Question

The potentiometer wire of length 800cm has a resistance of 40Ω.It is connected in series with a resistance of 10Ω and an accumulator of emf 2V having negligible resistance. A source of 1.5V is balanced against a length L of potentiometer wire. Find the value of L.​

Answer 1

Answer:

Correct option is

B

120cm

I=

R

V

=

10+20

6

=

30

6

=

5

1

A

Voltage across wire =6−

5

1

×10

=4V

Voltage per unit length =

200

4

=0.02v/s

Length for balancing =

2

2.4

×100cm

=120cm

Answer B