A variety of light bulbs contain mercury. Mercury is important in lighting since it helps to the efficiency and longevity of the bulbs. In general, fluorescent and other mercury-added bulbs are more energy efficient and last longer than incandescent and other comparable lights.
The choke's job is to create a very high voltage between the filaments at first (across the two ends of the tube light). The choke again delivers a low voltage after the gas in the tube is ionized. A choke is a wire coil. Mercury vapor fills fluorescent tubes and lights.
