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About Electricity
1. What is Electricity?
Q: So many things are connected to electricity, such as
lamps, TVs, and air conditioners. Can you tell me what
electricity is?
A: It can be defined as the movement of
sub-atomic
particles
(with
their
electrical charges) through a material
due to an electrical charge outside the
material. There are some examples in
our daily life, such as lightn ing and
static electricity.
2. Who Discovered Electricity?
Q: Who discovered electricity?
A: I am going to tell you a story that can be traced back to
at least 600 BCE. In ancient Greece, it was found that
rubbing fur on amber cause an attraction between the two. This
discovery is credited to the philosopher Thales of Miletus. One
day, when he was polishing his amber at home, he found that a
piece of fur was attracted by the amber after he
put it on the desk. Then he split them, but it
happened again. So he made record about the
phenomenon. It was to be many centuries before
anyone was able to connect this phenomenon
with electricity and a century more before
electrical current was put to practical use.
3. How to Categorize Electricity?
Q: Are we using the same electricity to power the air
conditioner and the remote control?
A: Good question! Actually they are totally
different. What we use in the air conditioner
is called alternating current, because
the flow of electric charge periodically
reverses direction. All home appliances
use alternating current; whereas, we use
direct current in the remote control, in
which the flow of electric charge is only in
one direction.
4. Wireless
Q: My parents tell me that the weather report is
transferred by the satellite, but I know it is impossible for
us to connect a wire to outer space. How do we
deliver these messages?
A: Wireless communication is the
transfer of information between two or
more points that are not connected by
an electrical conductor. So scientists
upload the information by wireless
waves, so it can transfer to wherever
they want.
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