Consider the situation shown in . The wires `P_1Q_1` and `P_2 Q_2` are made to slide on the rails with the same speed `5cm s^(-1). Find the electric current in the 19`Omega` resistorif (a) both the wires move towards right and (b) if `P_1 Q_1` moves towards left but `P_2 Q_2` moves towards right.

Explanation

(a) the wire constitute two parallel emf. `
`Net e.m.f =Blv`
`=1xx4xx10^-2)xx5xx10^(-2)`
`=20xx10^(-4)`
`Net resistance =(2+2)/(2+2)+19=20 Omega.`
`Net current =2xx10^(-4))/20=0.1 mA.`
`(b) when both wires towards opposite directions then net emf=0`
`..Net current =0.`