ObjectiveMcq
Print Protected
This page is protected for print. Use the website to view the content.
The energy meter works on the principle of ___________.
Correct Answer: D — Induction
The correct answer is D: Induction.
An energy meter operates on the principle of electromagnetic induction. It measures the amount of electrical energy consumed over a specific period (in kWh) and is essential for utility billing.
How it works:
Voltage Coil: Connected across the load; produces a magnetic field proportional to the applied voltage.
Current Coil: Connected in series with the load; generates a magnetic field proportional to the current through the load.
Interaction of Magnetic Fields: The interaction between these two magnetic fields induces eddy currents in an aluminum disc, creating a torque that causes the disc to rotate.
Disc Rotation: The rotational speed of the aluminum disc is directly proportional to power consumption — higher power means faster rotation.
Counting Mechanism: The disc rotation drives a gear mechanism that translates rotation into a numerical display of energy consumed in kilowatt-hours (kWh).