Question

A conducting rod is moved with a constant velocity v in a magnetic field. A potential difference appears across the two ends
(a) if →v ∥→l (b) if →v ∥→B (c) if →l ∥→B (d) none of these.

Answer 1

None of These is Answer

Explanation:

(d) Option is Answer

The potential difference across the two ends is given by

$e=B \times v \times l$

It is being a non-zero only.

(i)  On the off chance that the bar is moving in heading opposite to the attractive field ($\underset{v}{\rightarrow}\perp \underset{B}{\rightarrow}$)

(ii) In the event that the speed of the pole is toward the path opposite to the length of the bar

($\underset{v}{\rightarrow}\perp \underset{l}{\rightarrow}$)

(iii) On the off chance that the attractive field is opposite to the length of the pole  $\underset{l}{\rightarrow}\perp \underset{B}{\rightarrow}$

In this way, nothing unless there are other options conditions is fulfilled in the options given.