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In the following circuit, resistance of ...

In the following circuit, resistance of potentiometer wire is `100 Omega`. Power consumption in potentiometer wire is same when jockey is placed at 10 cm from end A or end B. Internal resistance of cell (r ) is

A

`30 Omega`

B

`6 Omega`

C

`60 Omega`

D

`3 Omega`

Text Solution

Verified by Experts

The correct Answer is:
A
a. Case I : 10 cm from A `P_1= (epsilon/(r+10))^2 xx 10`
Case II : 10 cm from B `P_2 = (epsilon/(r+90))^2 xx 90`
`P_1 = P_2 implies r = 30 Omega` .
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