CBSE Class 12 · 2011 · Electromagnetic InductionShort Answer

What are eddy currents? Write any two applications of eddy currents.

Solution

When a bulk conductor is placed in a changing magnetic field, the flux through it varies and induced currents circulate in closed loops within the body of the conductor; these are called eddy currents.
Their direction (Lenz's law) always opposes the change of flux that produces them.
Two useful applications:

Induction furnace — eddy currents heat and melt a metal placed in a high-frequency field.
Electromagnetic braking — eddy currents induced in a moving metal disc oppose its motion and bring it smoothly to rest.

CBSE Class 12 Board · 2011 · Subjective

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