Question

what is meaning of energy meter and write their working principle​

Answer 1

Answer:

Energy Meter or Watt-Hour Meter is an electrical instrument that measures the amount of electrical energy used by the consumers.

Explanation:

The energy meter has the aluminium disc whose rotation determines the power consumption of the load. The disc is placed between the air gap of the series and shunt electromagnet. The shunt magnet has the pressure coil, and the series magnet has the current coil.  The pressure coil creates the magnetic field because of the supply voltage, and the current coil produces it because of the current. The field induces by the voltage coil is lagging by 90º on the magnetic field of the current coil because of which eddy current induced in the disc. The interaction of the eddy current and the magnetic field causes torque, which exerts a force on the disc. Thus, the disc starts rotating. The force on the disc is proportional to the current and voltage of the coil. The permanent magnet controls Their rotation. The permanent magnet opposes the movement of the disc and equalises it on the power consumption. The cyclometer counts the rotation of the disc.