Background
One morning on October 21st,
1879, Thomas Edison sent a current of electricity through a carbon filament
in a glass globe, and that was the first light bulb that glowed. It was
an incandescent light bulb. Thomas Edison also developed many other things
such as cables, switches, sockets, junction boxes, wires, etc. Hence,
the light bulb was the beginning of many great ideas.
With all the problems with energy today and our
dependence on electricity, the invention of the energy saving light bulbs
developed. The energy saving light bulbs are compact, florescent lighting.
These bulbs last up to ten times longer than normal 60 watt light bulbs,
and they can come in different wave lengths that have different colours,
which are yellow, white or blue. Ten normal light bulbs equal one energy
saving light bulb. An energy saving light bulb, uses $13 of electricity
over its ten thousand hour life. An incandescent light bulb (60 watt)
would cost over $60 for the same time span.
There are many different kinds
of lasers, such as diode lasers, nitrogen lasers and light emitting lasers.
The laser is a special type of light with countless uses, such as holography.
As compared to light bulbs, mentioned before, a laser usually has one
wave length at a time. A laser light usually has a pure colour. The waves
are the same wave length and are in-step with each other. Lasers can also
emit an invisible or visible wavelength of light. Either way, the waves
spread out very little as they travel.
A solar cell, is a silicon semiconductor device,
that converts light energy directly into electricity. It is also a way
to measure light intensity when it attached to a volt metre.
Definitions
1. Light- A form of energy visible to the eye.
2. Luminous-. An object that
gives off its own light
3. Incandescent- Objects that
are luminous because they have a high temperature (ex. fire, incandescent
light bulbs, and the sun).
4. Laser- Energy from some source,
such as gas, is given to particles in the laser and when these particles
in the laser lose their extra energy, they emit in the form of a laser
light.
5. Wavelength- The length of
one wave.
6. Load- When electricity takes
energy from a source and delivers it to a useful device. That device
is a “load”.
7. Potential Drop- A measure
of the amount of energy given to a group of electrons to a load.
8. Potential Rise- A measure
of the amount of energy that leave the source.
9. Potential Difference- Either
a potential rise or a potential drop.
10. Volt- Both potential rise
and potential drop are measured in volts.
11. Voltmeter- An instrument
used to measure potential difference.
12. Current- A measure of how
many electrons pass through a wire or electric device each second.