Magnetic Braking — Eddy CurrentHardQuestion 20245
Question
When a metal plate is swung into a magnetic field, it slows down due to:
- AFriction between plate and field
- BInduced eddy currents that oppose the motion (Lenz's law)Correct
- CReduced kinetic energy from gravity
- DStatic magnetic repulsion
Correct answer
Induced eddy currents that oppose the motion (Lenz's law)
Explanation
Moving the conductor through a magnetic field induces eddy currents (by Faraday's law). By Lenz's law, these currents create a field that opposes the motion — an electromagnetic braking effect used in braking systems and damping.