Question

The shiny metal disk in the electric power meter (analog type) rotates due to:

• A. temperature change
• B. eddy currents
• C. an external motor
• D. pressure change

Hint:

Eddy currents are induced in a conductor moving in a magnetic field, often used in devices like electric meters and transformers.

Answer 1

The Correct Option is B

We need to determine the cause of rotation of the shiny metal disk in an analog electric power meter.
Step 1: Identify the working principle.
An analog electric power meter uses an aluminum disk that rotates due to the interaction of magnetic fields from two coils (voltage and current coils).
Step 2: Determine the cause of rotation.
The magnetic fields induce eddy currents in the disk. These eddy currents interact with the fields, producing a torque that causes rotation.
Final Answer: \[ \boxed{\text{eddy currents}} \]