A `0.1 m` long conductor carrying a current of `50 A` is perpendicular to a magentic field of `1.25 mT`. The mechanical power to move the conductor with a speed of `1ms^(-1)` is

Options

A. `62.5 mW`
B. `625 mW`
C. `6.25 mW`
D. `12.5 mW`

Answer

C

Explanation

Here, l = 0.1m, v = 1 `ms^(-1)`
I = 50 A and B = 1.25 mT = `1.25xx10^(-3)T`
The induced emf is, `epsilon=Blv`
The mechanical power is,
`P=epsilonI=BlvI=1.25xx10^(-3)xx0.1xx1xx50`
`=6.25xx10^(-3)W=6.25mW`