Choke Coil

As energy is being dissipated to the surrounding them resistance

I = 0.5 A

V = 200 volt

I = V                Z = 400Ω

Z² = R² + X_L²

160000 = 40,000 + X_L²

X_L = 200√3               X_L = LW

To control the current in AC circuit resistance can be used but due to it’s maximum  power factor it consumer power which is dissipated in the form to heat Hence is considered as loss.

To save this power loss in place of resistance pure inductance can be used to control the current. Due to it’s 0 power factor it doesn’t consume any power. Hence no power loss taken place such an inductance is known as choke coil. It value can be calculated as shown is above example.