Same current i is flowing in the three infinitely long wires along positive x-,y- and z-directions. The magnetic filed at a point (0,0,-a) would be

Options

A. `(mu_(0)i)/(2pia)(hat(j)-hat(i))`
B. `(mu_(0)i)/(2pia)(hat(i)+hat(j))`
C. `(mu_(0)i)/(2pia)(hat(i)-hat(j))`
D. `(mu_(0)i)/(2pia)(hat(i)+hat(j)+hat(k))`

Answer

1

Explanation

Magnetic field due to current along the `z-` axis is 0.
and due to rest two wires is `(mu_(0))/(2pi)(i)/(a)`
`B_(x)=(mu_(0)i)/(2pia)hat(j),B_(y)=(mu_(0)i)/(2pia)(-hat(i)),B_(z)=0`