Two concentric coils each of radius equal to `2pi` cm are placed at right angles to each there. 3 A and 4 A are the currents flowing in each coil respectively.
The megnetic induction in `Wb//m^(2)` at the centre of the coil will be `(mu_(0) =4pi xx10^(-7)Wb//Am)`

Options

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

Answer

C

Explanation

Magnetic field or magnetic induction at P,
`B_(p)=(mu_(0)I_(2))/(2R)=(4pixx10^(-7)xx4)/(2xx0.2pi)=4xx10^(-5)Wb/m^(2)`
and `B_(Q)=(mu_(0)I_(1))/(2R)=(4pixx10^(-7)xx3)/(2xx0.002pi)`
`=3xx10^(-5)Wb//m^(2)`
`:. B=sqrt(B_(P)^(2)+B_(Q)^(2))=sqrt((4xx10^(-5))^(2)+(3xx10^(-5))^(2))`
`5xx10^(-5)Wb//m^(2)`