Two concentric coils each of radius equal to `2 pi cm` are placed at right angles to each other ` 3 ampere and 4 ampere` are the currents flowing in each coil respectively. The magnetic induction in `weber//m^(2)` at the centre of the coils will be
`( mu_(0) = 4 pi xx 10^(-7) Wb// A.m)`

Options

A. `5xx10^(-5)`
B. `7xx10^(-5)`
C. `12xx10^(-5)`
D. `10^(-5)`

Answer

A

Explanation

`B_("net") = sqrt(B_(1)^(2) + B_(2)^(2)) = (mu_(0))/(4pi), (2pi)/(r) sqrt(i_(1)^(2) + i_(2)^(2))`
`= 10^(-7) xx (2pi)/(2pi xx 10^(-2)) sqrt((3)^(2) + (4)^(2))`
`= 5xx10^(-5) wb//m^(2)`