The choke is an induction coil and along with the starter, helps develop the high voltage needed to fire the spark between the two electrodes in the tube light. In electronic chokes, the starter is included in the choke. An incandescent lamp is a simple resistance that gets heated by the passing of the current. So, it works over a wide range of voltage, esp. low voltages but the brightness goes down.

The choke has two main functions. It (in conjunction with the starter if it has one) causes the tube to ignite by using the back emf to create a plasma in the tube and it controls the current through the tube when it is ignited.

In a gas discharge, such as a fluorescent lamp, current causes resistance to decrease. This is because as more electrons and ions flow through a particular area, they bump into more atoms, which frees up electrons, creating more charged particles. In this way, current will climb on its own in a gas discharge, as long as there is adequate voltage (and household AC current has a lot of voltage). If the current in a fluorescent light isn't controlled, it can blow out the various electrical components.

Bulbs have filaments hence there is no need lets see, A 60 watt incandescent bulb produces light by heating a tungsten filament. A review by Denardo suggests that the temperature of the filament of a 60 W bulb is 2780 K. If you treat it as a blackbody radiator ...more

Now a days electronic chkoes are available, They are useful in case of T-5 lamps,
Which are enrgy efficient and usful when volatge is low.particularly when reactive power sharing problem is there.