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In a wire of cross-section radius r, fre...

In a wire of cross-section radius `r`, free electrons travel with drift velocity `v` when a current `I` flows through the wire. What is the current in another wire of half the radius and of the same material when the drift velocity is `2v`?

A

`2I`

B

`I`

C

`I//2`

D

`I//4`

Text Solution

Verified by Experts

The correct Answer is:
C
`I_(1)="ne" A_(1)v_(d_(1)) & I_(2)="ne" A_(2)v_(d_(2))`
`I_(2)/I_(1)=A_(2)/(A_(1))xxv_(d_(2))/v_(d_(1))=1/4xx(2v)/vimplies I_(2)=I/2`
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