Choke coil is used to control

Explanation

Choke coil is connected in series with the tube light and its presence reduces voltage across the tube light. We need low voltage to operate tube light.
If rms votlage applied is `epsilon_("rms")`, then we can write rms voltage across tube light as follows :
`rArr " " V_(rms)^("tube -light ") = (R)/( sqrt( R^(2) + m^(2) l^(2),) ) epsilon_(rms) `
Voltage across tube light is less than applied, and the same can be understood by the above equation. Ideally inductor does not consume power , so voltage reduction across tube light is done without wastage of any power. but is there but it is small .