A rod PQ of length L moves with a uniform velocity v parallel to a long straight wire carrying a current i, the end P remaining at a distance r from the wire. The emf induced across the rod is

\[\frac{{{\mu }_{0}}iv}{2\pi }ln\,\left( \frac{{{r}^{2}}+{{L}^{2}}}{{{L}^{2}}} \right)\]

\[\frac{{{\mu }_{0}}i{{v}^{2}}}{2\pi }ln\,\left( \frac{r+L}{R} \right)\]

\[\frac{{{\mu }_{0}}iv}{2\pi }ln\,\left( \frac{r+L}{R} \right)\]

A rod PQ of length L moves with a uniform velocity v parallel to a lon

1.	A rod PQ of length L moves with a uniform velocity v parallel to a long straight wire carrying a current i, the end P remaining at a distance r from the wire. The emf induced across the rod is
A.	\[\frac{{{\mu }_{0}}i{{v}^{2}}}{2\pi }ln\,\left( \frac{r+L}{R} \right)\]
B.	\[\vec{B}\]
C.	\[\frac{{{\mu }_{0}}iv}{2\pi }ln\,\left( \frac{r+L}{R} \right)\]
D.	\[\frac{{{\mu }_{0}}iv}{2\pi }ln\,\left( \frac{{{r}^{2}}+{{L}^{2}}}{{{L}^{2}}} \right)\]
Answer» D. \[\frac{{{\mu }_{0}}iv}{2\pi }ln\,\left( \frac{{{r}^{2}}+{{L}^{2}}}{{{L}^{2}}} \right)\]