A horizontal overheadpowerline is at height of `4 m` from the ground and carries a current of `100 A` from east to west. The magnetic field directly below it on the ground is
`( nu_(0) = 4 pi xx 10^(-7) Tm A^(-1)`

Options

A. `2.5xx10^(-7)T` southward
B. `5.0xx10^(-6)T` northward
C. `5.0xx10^(-6)T` southward
D. `2.5xx10^(-7)T`, northward

Answer

C

Explanation

`B=(mu_(0)I)/(2pir)=2xx10^(-7)xx100/4=5xx10^(-6)T`, southward