Question

Changing magnetic fields can set up current loops in nearby metal bodies. They dissipate electrical energy as heat. Such currents are called

• A. Eddy currents
• B. Self-induced currents
• C. Photo currents
• D. Ionic currents

Hint:

Eddy currents = circulating currents induced in conductors by changing magnetic fields → heat generation.

Answer 1

The Correct Option is A

When a conductor is placed in a changing magnetic field, circular electric currents called eddy currents are induced in the body of the conductor. These currents circulate within the conductor and dissipate energy in the form of heat.
This principle is used in devices like:
- Induction cooktops
- Magnetic brakes
- Eddy current dampers

Answer 2

Step 1: Understand the phenomenon
When a changing magnetic field passes through a nearby metal conductor, it induces circulating currents in the metal.

Step 2: Explain the nature of these currents
These induced currents flow in closed loops within the conductor.
Because the metal has resistance, these currents cause energy dissipation in the form of heat.

Step 3: Name of such currents
These induced currents are known as Eddy currents.

Step 4: Applications and effects
Eddy currents are used in induction heating, electromagnetic braking, and metal detectors.
However, they can cause unwanted energy loss in transformers and electric motors.

Final conclusion
Thus, changing magnetic fields induce Eddy currents in nearby metal bodies which dissipate electrical energy as heat.