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When a current I flows through a wire, t...

When a current I flows through a wire, the drift velocity of the electrons is v. When current 2I flows through another wire of the same material having double the length and double the area of cross-section, the drift velocity of the electrons will be

A

`(v)/(8)`

B

`(v)/(4)`

C

`(v)/(2)`

D

v

Text Solution

Verified by Experts

The correct Answer is:
D
`I=n eAv_(d)`
or `v_(d)=(I)/(n eA)`
or `v_(d)prop(I)/(A)`
`therefore (v._(d))/(v_(d))=((I.)/(A.))/((I)/(A))`
`=((2I)/(2A))/((I)/(A))=1`
or `v._(d)=v_(d)=v`
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Knowledge Check

  • When the number of turns and the length of the solenoid are doubled keeping the area of cross section same the self inductance is

    A
    halved
    B
    doubled
    C
    remains the same
    D
    becomes four times

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