Electrical choke is a very much known word to us. But many people do not know about choke. Let’s learn about electrical choke.

## What is Electrical Choke?

Electrical choke is a coil or Inductor. A conductor wound on a core with a number of turns can be called Choke. The electrical choke works same as an inductor. When the current flowing through the choke coil and it changes continuously then a magnetic field is produced which work against the flowing current. As the AC current changes continuously the choke coil try to block the AC current. As the DC does not change so the choke coil easily passed it. For this property of the choke coil, it is used to filtrate the output of a Rectifier.

A choke coil or inductor also has a property similar to a capacitor, both of them store charges passing through them. A choke coil stores electrical charge by creating a magnetic field around it. A capacitor does not work so.
Now a day’s Electronic Choke is used.

## Why Choke coil used in Fluorescent tube light?

1. Choke coil is connected in series with the tube light. It limits the current at starting time during the closed condition of the bimetallic contact in the starter.

2. A high voltage is necessary to get ionized gas inside the tube light. The choke coil creates high voltages across it and helps to ionization of the gas.
Now a day’s Electronic Choke is used in Fluorescent tube light.

## Effect of AC and DC on Electrical Choke coil:

As a choke coil is an inductor so it tries to block the AC current but in the case of DC it does not give any resistance to flow of DC current.
Let’s understand it mathematically,
We know the inductive reactance ( it is the resistance offered by an inductor) XL=2Ï€fL
‘f’  is the frequency and ‘L’ is the inductance.
As AC has the frequency, so the inductor gives resistance to the AC. But in the case of DC, it has no frequency, so the inductor does not give any resistance to the flow of DC current.

## Applications of Electrical Choke coils:

1. It is used to filtrate output of Rectifier and provide pure DC output.
2. For its magnetic property, it is used in Relays, Circuit breakers etc.
3. It is used in the devices which are used in radio stations.
4. It is used in resonance circuits.
5. It is used in signals transmission systems.