Question

A metal rod moves at a constant velocity in a direction perpendicular to its length. A constant uniform magnetic field exists in space in a direction perpendicular to the rod as well as its velocity. Select the correct statement(s) from the following

• A. The entire rod is at the same electric potential
• B. There is an electric field in the rod
• C. The electric potential is highest at the centre of the rod and decreases towards its ends
• D. The electric potential is lowest at the centre of the rod and increases towards its ends

Answer 1

Answer: (B)

There is an electric field in the rod

Answer 2

A motional emf $e = Bvl$is induced in the rod, or we can say, a potential difference is induced between the two ends of the rod AB, with P at higher potential and Q at lower potential. Due to this potential difference, there is an electric field in the rod.