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A wire of length 100 cm is connected to...

A wire of length 100 cm is connected to a cell of emf 2 V and negligible internal resistance. The resistance of the wire is `3 Omega`. The additional resistance required to produce a potential drop of 1 milli volt per cm is

A

`60 Omega`

B

`47 Omega`

C

`57 Omega`

D

`35 Omega`

Text Solution

Verified by Experts

The correct Answer is:
C
`l = 2/(3 + R)`
`V/L = 1/100 ((2 xx 3)/(3 + R)) rArr 10^(-3) = 1/100 (6/(3 + R))`
`rArr 3 + R =60 rArr R = 57 Omega`
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