what is choke coil

What is a choke coil ?

When an alternating voltage of 100V, 50 Hz is applied to a choke coil, it takes a current of 10 A and the power is 500 W. What is the choke coil?

Why is choke coil needed in the use fluoresent tube with ac mains ?

An electric lamp which runs at 100 V DC and consumes 10 A current is connected to AC mains at 150 V, 50 Hz cycles with a choke coil in series. Calculate the inductance and drop of voltage across the choke. Neglect the resistance of choke.

A capacitor of capacitance 250 pF is connected in parallel with a choke coil having inductance of 1.6 xx 10^(-2) H and resistance 20 Omega . Calculate (a) the resonance frequency and (b) the circuit impedance at resonance.