How does a choke work in a tube light circuit?

The choke works in conjunction with a starter . When you turn on the light , voltage is applied to the choke, and when the switch opens after a few seconds, it creates a high voltage across the contacts at each end of the tube. This starts the ionization of the gas , which glows. Once ionized, it continues producing light even when the voltage applied is only 120 VAC, the power line voltage.