The force between two long parallel wires A and B carrying current is `0.004 Nm^(-1)`. The conductors are `0.01 m` apart. If the current in conductor A is twice that of conductor B, then the current in the conductor B would be

Options

A. `5 A`
B. `50 A`
C. `10 A`
D. `100 A`

Answer

C

Explanation

Force per unit length.
`(F)/(l)=(mu_(0))/(2pi)(i_(A)i_(B))/(r)`
Given,
`i_(A)=2i_(a)`
`:. (0.004)=(2xx10^(-7))/(0.01)(2i_(B)^(2))`
`:. i_(B)=10A`