^Choke coil

A coil having large inductance & small resistance connecting it in series with a fluorescent tube in order to control current in it  without appreciable power loss.

Application of chock coil A resistor due to larger power dissipation is not used. For a normal inductor consumes power smaller than consumed by a resistor by a factor of

As thus for a given emf to reduce low frequency alternating current the choke coils with high inductance i.e. inductors with soft iron cores are used & for reducing high frequency alternating currents the choke coils with low inductance i.e. inductors with air as core are used .