A square loop of side a carris a current `I`. The magnetic field at the centre of the loop is

Options

A. `(2mu_(0)Isqrt(2))/(pia)`
B. `(mu_(0)Isqrt(2))/(pia)`
C. `(4mu_(0)Isqrt(2))/(pia)`
D. `(mu_(0)I)/(pia)`

Answer

A

Explanation

`B_(C)=4[(mu_(0))/(4pi)I/(a//2)(sin 45^(@)+sin 45^(@))]=(2sqrt(2)mu_(0)I)/(pia)`