Figure shows a long wire bent at the middle to form a right angle. Show that the magnitudes of the magnetic fields at the points P,Q, R and S are equal and find this magnitude. `

Explanation

At point P, B due to `W_1 = 0`
`. B due to `W_2` `= (mu_0i)/(2pid)` along `ox`
`. so, net `B = (mu_0i)/(2pid) along `ox`
`. At point Q, B due to `W_1 = (mu_0i)/(2pid)` along `ox`
`. B due to `W_2` = 0`
`. So , net B = (mu_oi)/(2pid) along`
`. At point R, B due to `W_1 = 0` B due ot `W_2= (mu_oi).(2pi) along`
`. Hence net B =(mu_oi)/(2pid) along`
`. At point S, B due to W = (mu_oi)/(2pid) along `ox`
`B` due to `W_2 = 0`.
So, net `B=(mu_oi)/(2pid)along ox`.
Clearly magnitude of `B` at each `P, Q, R and S` is `(mu_oi)/(2pid)`.