Question

An electron moves along the line PQ which lies in the same plane as a circular loop of conducting wire, as shown in Fig. 25.5. What will be the direction of the induced current, if any, in the loop?

• A. Anti-clockwise
• B. Clockwise
• C. Alternating
• D. No current will be induced in the loop.

Answer 1

The correct option is A. Anti-clockwise

Since the charge of an electron is negative, the moving electron constitutes a current in the direction opposite to the direction of motion of the electron,

i.e. the direction of the current will be from Q to P. The magnetic field threading the coil due to the motion of the electron will be directed into the plane of the page, i.e. perpendicular to the plane of coil directed into the page. To oppose this, the current in the coil must be anticlockwise, in accordance with Lenz's law.