Headings Electromagnetism Induced Current Search Questions 
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Transmission - Energy Loss.
A generator at a power
station might produce electricity
with a voltage
of 25,000V and a current of 8,000A.
Such a large
current would cause the cables
of the National Grid
to get hot because of the heating effect of current.
Energy would then be lost as heat to the
atmosphere
and by the time that the electricity had traveled
from the power station through the
cables to the towns and factories,
much of the original energy would be
lost.
To reduce the energy
loss, a step up
transformer at the power station
is used to raise the voltage to 400,000V.
This is 16 times the input voltage of 25,000V.
The power equation tells
us
that if the voltage has gone
up by 16
times,
then the current must be reduced by 16
times.
The original current of
8,000A is reduced to
8000 ÷ 16 =
500A.
This current is still high but the thickness of the cables
means that the heating effect is
minimal.
At factories, a step down transformer reduces
the voltage to 33,000V.
For houses, a step down transformer
reduces the voltage to 240V.
The electricity produced by
power stations is alternating current
because
1. It is easy to generate alternating current.
2. Transformers will not work with
direct current.
Headings Electromagnetism Induced Current Search Questions
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