Question

A metallic square loop ABCD is moving in its own plane with velocity v in a uniform magnetic field perpendicular to its plane as shown in the figure. An electric field is induced
A. In AD, but not in BC
B. In BC, but not in AD
C. neither in AD nor in BC
D. In both AD and BC

Answer 1

In order to solve the question, we will use the flow of electron so as to find that electric field is produced in which part of the square metallic loop and we also use the concept of the Lorentz force to see the potential difference and flow of current in each of the part of the loop.

Complete answer:
In the question we are given that a metallic square loop ABCD is moving in its own plane with velocity $v$ in a uniform magnetic field perpendicular to its plane and we have to find the electric field in which parts of metallic square loop ABCD.

The square loop ABCD is the metallic loop that is why it consist of free moving electron when magnetic field is around the area and the loop moves in the magnetic field when this happens free electron will move in the rod AB and BC because of this both the rods AB and BC experiences the Lorentz force and these electrons will move toward the ends of the rods so as to create the potential difference.The induced emf results in inducing the electric field in the rods AB and BC of the square metallic loop ABCD there is no flow of current in the square loop as net potential difference is zero

Hence, the correct option is D.

Note: Many of the students will make the mistake by not taking the potential difference zero. This fact is not considered because people forget that there is no flow of current. This confusion arises because there is induced electromotive force but it doesn’t change the potential difference.