Image: iStockphoto.com/Ivan Stevanovic
About This QuizLighting uses energy in various ways to enhance what we see around us. Take this quiz to determine see how enlightened you are about lighting.
What is the main reason why a regular incandescent bulb is not energy efficient?
Most of the electricity is used to make the gas reactive.
Most of the electricity goes into heating the filament.
Much of the electricity used in an incandescent bulb turns into heat instead of light. Since the main function of a light bulb is to provide light, all of the heat generated is considered a waste of energy.
Most of the electricity used to overcome fluorescence.
What happens to an incandescent bulb to cause it to burn out?
The tungsten filament is slowly vaporized, leaving a thin spot that eventually breaks.
During the process of making light the tungsten filament is slowly vaporized onto the glass bulb until the filament is so thin that it breaks. When the filament breaks, the electric circuit is open and electricity no longer flows to illuminate the bulb.
The gas in the bulb is slowly depleted until there is not enough to create light.
The bulb gets hotter with each use until the solder attaching the filament melts.
On average, how many hours of normal usage do you get from an incandescent bulb?
400 to 650 hours
600 to 950 hours
750 to 1,000 hours
An incandescent bulb will average 750 to 1,000 hours of usage.
Why is the envelope of the halogen bulb made from quartz?
A glass envelope contains impurities that react to the halogen gas.
A glass envelope crystallizes when subjected to halogen gas.
A glass envelope will melt from the intense heat.
Halogen bulbs are more compact, which places the filament very close to the envelope. A glass envelope would melt due to the increased exposure to heat.
What is the effect on a heated tungsten filament when used in a bulb filled with halogen gas?
The halogen gas forms a protective coating on the filament.
The halogen gas atoms combine with vaporized tungsten and deposit it onto the filament.
Inside a hot bulb, the vaporized tungsten combines with the halogen gas atoms and is deposited back onto the filament. This process insures that the halogen bulb lasts much longer than its incandescent cousin by regenerating the filament.
The halogen gas prevents the filament from releasing any vaporized tungsten.
Approximately how many lumens of light per watt does an incandescent bulb generate?
Incandescent bulbs give approximately 15 lumens of light per watt of input electricity. Incandescent bulbs get so hot that ovens made for children often use these light bulbs to cook the food.
How many electrodes are contained in a fluorescent tube?
A fluorescent tube contains two electrodes. During the process of creating light electrons move between the two electrodes.
What are the two gases contained in a fluorescent tube?
argon and mercury
Fluorescent tubes contain the inert gas argon and a small amount of mercury, which changes from a liquid to a gas when an electric current passes through it.
halogen and nitrogen
mercury and nitrogen
produce far more heat than incandescent bulbs
produce far less heat than incandescent bulbs.
Fluorescent bulbs produce far less heat and far more light than incandescent bulbs. Large buildings use fluorescent lights not only for their efficiency, but also because less heat means lower air conditioning costs.
produce approximately the same amount of heat as incandescent bulbs.
What is the primary purpose of the argon gas inside the fluorescent tube?
The argon gas produces light when the electrons excite it.
The argon gas provides the pressure that keeps the phosphor coating in place.
The argon gas allows the electrons to flow between the electrodes.
The argon gas allows electrons to flow from the electrode at one end of the tube to the electrode at the other end.
What is the purpose of the mercury gas contained within the fluorescent tube?
Atoms of mercury gas generate ultraviolent photons when they are excited.
When mercury atoms move from an excited state to an unexcited state they give off ultraviolet photons.
Atoms of mercury gas generate visible light when they are excited.
Atoms of mercury gas collide with argon atoms to generate light.
What is the purpose of the phosphorus coating on the glass of a fluorescent tube?
prevents the mercury atoms from escaping through the glass
gives fluorescent tubes that nice clean white color
makes ultraviolet light visible
The phosphorus coating is responsible for changing the ultraviolet protons to visible light.
What is the primary difference between neon tubes used on signs and fluorescent tubes?
Neon tubes are virtually the same as fluorescent tubes.
Neon tubes produce light directly from neon gas.
Neon tubes use high voltage to produce light directly from neon gas and do not rely on additional gases or coatings.
The primary difference is the phosphorus coating is tinted various colors.
Why is electroluminescence a more efficient form of light production than incandescence?
Electricity is converted directly to light.
Electroluminescence is more efficient because it produces light directly from electricity, rather than by heating a filament as in incandescence.
Only half as much heat is generated while producing light.
There is less electricity wasted during startup.
The Indiglo light contained in a Timex watch is an example of:
The Indiglo light is a perfect example of simple electroluminescence. The watch uses an electric current to energize phosphor ions so that they emit a soft glow.
How many lumens of light per watt does a standard florescent tube produce?
40 to 80
50 to 100
A standard florescent tube produces 50 to 100 lumens per watt, compared to 15 lumens per watt by incandescent bulbs. Not only are fluorescent tubes cool, they are very bright!
75 to 150
How many filaments are contained within a three-way incandescent bulb?
The name used for a three-way bulb often throws people a curve ball. The three-way bulb contains only two filaments.
The brightness of a three-way bulb is determined by:
the amount of voltage sent to the bulb
a photocell sensor contained within the bulb
the position of the switch on the lamp
The position of the switch on the lamp determines the brightness of the bulb. At the maximum position, both filaments are lit.
What would be the typical filament combination inside a bulb rated at 150-watts maximum output?
one 100-watt and two 50-watt
one 100-watt and one 50-watt
A typical three-way bulb rated at a maximum output of 150-watts contains one 50-watt filament and one 100-watt filament. The low setting energizes the 50-watt filament, the medium setting energizes the 100-watt filament and the maximum setting energizes both the filaments.
How much more efficient are fluorescent tubes in producing light than a typical incandescent light?
four to six times
Fluorescent tubes produce four to six times more light than an incandescent bulb with the same wattage rating. The increased efficiency applies to regular tubes, circular tubes and the newer compact fluorescent bulbs.
eight to 10 times
10 to 20 times