What is the nature of current coil and voltage coil of wattmeter?

In electrodynamometer type wattmeter, moving coil works as pressure coil. Hence moving coil is connected across the voltage and thus the current flowing through this coil is always proportional to the voltage.

What is current coil in wattmeter?

Wattmeter usually consists of two coils known as Current coil and Potential coil. The Current coil is connected in series with the electric circuit whereas the movable Potential coil is connected in parallel. The current flows through the Current coil generating an electromagnetic field around the coil.

What will happen if we interchange potential coil and current coil in a wattmeter?

In the question given that, the current and potential coils of a dynamometer type wattmeter were accidentally interchanged while connecting. Hence total voltage applies across current coil which has very less resistance which leads to damage the current coil.

Why resistance of current coil is less and voltage coil is high?

The resistance of current coil is minimum because it is always connected in series and if its resistance is high then there will be a more voltage drop and power loss so keeping the resistance low helps in less power loss.

What is potential coil?

Definition of potential coil : a coil or winding connected in shunt across a circuit (as in a wattmeter)

How many coils are in a wattmeter?

two coils
The Electrodynamometer wattmeter has two coils i.e., fixed and moving coils. The fixed coil is connected in series with the circuit in order to measure power consumption.

What is current coil and potential coil?

The traditional analog wattmeter is an electrodynamic instrument. The device consists of a pair of fixed coils, known as current coils, and a movable coil known as the potential coil. The current coils are connected in series with the circuit, while the potential coil is connected in parallel.

What happens if you change pressure and current in a coil?

Firstly, the circuit wont work since potential coil has very high resistance and if it is used in place of current coil the current flow in circuit drops close to zero. More importantly there is a very high possibility of the wattmeter getting damaged due to flow if excess current in current coil.

Why potential coil is always connected in parallel?

In order for a voltmeter to measure a device’s voltage, it must be connected in parallel to that device. This is necessary because objects in parallel experience the same potential difference.

What is difference between current coil and voltage coil?

The current coil is connected in series with the load and the pressure coil is connected in parallel with the load. Current is measured by the current coil and voltage is measured by the pressure coil. A pointer which experiences the effect of both these coils, moves in the wattmeter scale.

What is a current coil?

A current coil is basically a coil, such as, a wire wrapped around an electrical conductor. Usually, the coil is made out of insulated copper wire and the conductor is a soft iron core. This property of a conductor, when wrapped around a current-carrying coil, is called electromagnetism.

How many coils are there in single phase wattmeter?

A wattmeter principally consists of two coils, one coil is called the current coil, and the other the pressure or voltage coil.

What is the difference between current coil and potential coil?

The current coils are connected in series with the circuit, while the potential coil is connected in parallel. The moving coil moves the pointer with the help of spring control instrument. Its connected across the voltage and hence a proportional current flows through this coil.

What is the potential coil on a watt meter?

The potential coil on a watt meter is like the input of a volt meter, that is, it has a high input impedance, is intended to be connected across the input power line or across the load, and draws little current.

What happens if you connect a current coil to an ammeter?

If the current coil is connected across the input power line, its very low impedance (like an ammeter has) will be very nearly a short circuit across the power line and a very large current, much more than intended, will flow in the current coil.

Why can’t pressure and current coils be connected in series?

Pressure coil ( or the moving coil) must carry a low value of current and current coil ( or fixed coil) usually carries a high current. Since current flowing in series remains the same therefore these two cannot be connected in series and are hence conneced in parallel.