Zero, because force and displacement are in mutually perpendicular directions.
Class 12 Physics NCERT Sample Paper Question Session 2024-2025.
An electron with charge e and mass m travels at a speed v in a plane perpendicular to a magnetic field of magnitude B. The electron follows a circular path of radius R. In a time ‘t, the electron travels halfway round the circle. What is the amount of work done by the magnetic field?
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The work done by the magnetic field on the electron is zero. This is because the magnetic force is always perpendicular to the velocity of the electron, resulting in no displacement along the direction of the force, hence no work is done.
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