Find the current in the wine PQ for the configuration as shown in the fig. Wire PQ has negligible resistance. B, the magnetic field is coming out of the paper. $\theta$ is a fixed angle made by PQ travelling smoothly over two conducting parallel wires separated by a distance d.

Question

(a) I = $\frac {d \vartheta R}{B}$
(b) $\frac {\vartheta B}{dR}$
(c) $\frac {R}{d \vartheta B}$
(d) $\frac {d \vartheta B}{R}$