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

(a)
`B_x=(mu_0)/2 I/(2pixx10^-2)=(mu_0)/(4pi) 3xx10^2=3xx10^-5T`
`B_y=(mu_0)/2 I'/(2pixx10^-2)=4xx10^-5T`
`B_(n et)=sqrt(B_x^2+B_y^2)=sqrt(25xx10^-10)=5xx10^-5T`