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)/rsqrt(i_(1)^(2)+i_(2)^(2))`
`=10^(-7)xx(2pi)/(2pixx10^(-2))sqrt((3)^(2)+(4)^(2))=5xx10^(-5) Wb//m^(2)`