What is the energy source for an incandescent bulb?
a wire filament
Is it hot?
yes
How does it get hot?
by passing an electric current through it
How is is protected?
with a glass or quartz bulb that is filled with inert gas or evacuated.
How about in a halogen bulb?
a chemical process
How does the bulb get its energy supply?
by feed-through terminals or wires embedded in the glass.
Are incandescent lights efficient?
no
How much energy do they convert to light?
less than 5%
What happens to the rest of the energy?
it is converted into heat
How many lumens per watt does an incandescent bulb create?
16
What about a fluorescent bulb?
60 lm/W
An LED bulb?
150 lm/W
What are other uses of incandescent bulbs?
incubators, brooding boxes for poultry, heat lights for reptile tanks
How long does an incandescent bulb last?
around 1,000 hours
What about fluorescent?
10,000 hours
And LED?
30,000