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 $\overrightarrow{v}||\overrightarrow{l}$
• B. if $\overrightarrow{v}||\overrightarrow{B}$
• C. if $\overrightarrow{l}||\overrightarrow{B}$
• D. none of these

Answer 1

The correct option is D none of these

A potential difference appears across the two ends if a component of length of rod and the a component of velocity of the rod and a component of magnetic field all mutually perpendicular.
that is $(\overrightarrow{l}\times \overrightarrow{v}).\overrightarrow{B}\ne 0$