Which type of wattmeter primarily consists of two elements: one for current and the other for voltage?

The electrodynamometer type wattmeter is designed to measure electrical power by utilizing two essential elements: a current coil and a voltage coil. The current coil is responsible for measuring the current flowing through the circuit, while the voltage coil measures the voltage across the load.

The operation of an electrodynamometer wattmeter is based on the interaction between the magnetic fields produced by these two coils. When current flows through the current coil, it generates a magnetic field, and when voltage is applied across the voltage coil, it interacts with the magnetic field of the current coil. This interaction produces a torque that is proportional to the product of the voltage and current, allowing for accurate power measurement.

This design is significant because it enables the wattmeter to measure both AC and DC power accurately, making it versatile for various applications. The characteristics of the electrodynamometer also ensure accurate performance over a wide range of frequencies and power factors.