Two wires P Q and Q R , carry equal currents I as shown in figure. One end of both the wires extends to infinity P Q R= . The magnitude of the magnetic field at O on the bisector of these two wires at a distance r from point O is

Step-by-step solution

Perpendicular of O from P Q or Q R , a=r / 2 magnetic field induction at O due to current through P Q and Q R is aligned B & = ₀ 4 1 a [ (90^ - / 2 )+ 90^ ] 2 & = ₀ 2 1 r / 2 ( / 2+1) & = ₀ 2 l r (1+ / 2) / 2 aligned