(A) Instructions: Read the following passage and answer the questions. (4 marks)
Incandescent bulbs produce light when an electric current passes through a filament (ไส้หลอด) and causes it to glow. Because they are less energy-efficient than other light sources, they are best used for task lighting that demands high levels of brightness. Incandescent bulbs are of three types.
General Service bulbs are the inexpensive, readily available light bulbs that most of us think about when we hear "light bulb." They produce a warm, yellow-white light that goes in all directions. They are available in either a clear or frosted finish. They have three basic shapes: General (A), Globe (G), and Decorative.
Reflectorized bulbs have a reflective coating (การเคลือบ) inside the bulb that directs the light in one direction rather than all around. They give approximately double the amount of light as General Service of same wattage. Reflectorized bulbs are of two types. The first one is Parabolic Reflector (PAR) bulbs. They control light more precisely and produce about four times the light of General (A). The second is Tungsten-halogen bulbs. They produce a brighter and whiter light than other incandescent bulbs. They also have a longer life and provide more light per watt than standard incandescent bulbs. Therefore, they are a more efficient choice. Halogen bulbs are available in two types: line voltage (120 watt) and low voltage (12 volt).
Xenon bulbs have a white light similar to that of halogen but have a much longer life rating (some up to 20,000 hours, much like fluorescent) and work at lower temperatures than halogen.
B) Instructions: Fill the diagram of a classification of incandescent bulbs. (2 marks)