Headings Electromagnetism Induced Current Search Questions 
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Transformer Equation.
This equation is important!
The transformer equation
relates the number of turns
of wire
to the difference in voltage
between the primary and secondary
coils.
Vp/Vs = Np/Ns
Where Vp
is the voltage in the primary
coil.
Vs is the voltage in
the secondary coil.
Np is the number of turns
of wire on the primary coil.
Ns is the number
of turns of wire on
the secondary coil.
There are two points to remember.
1. Transformers
only work with alternating current.
Using direct current will
create a magnetic field in the core
but it will not be a changing
magnetic field
and so no voltage will
be induced in the secondary
coil.
2.
Using a step up
transformer to increase the voltage
does not give you something
for nothing.
As the voltage goes up,
the current goes down
by the same proportion.
The power equation shows that the overall
power remains the same,
P = V x I Power = Voltage x Current.
In reality, the power
output is always less than the power
input
because the changing magnetic field in the core
creates currents (called eddy
currents) which heat the core.
This heat is then lost
to the environment, it is wasted
energy.
Headings Electromagnetism Induced Current Search Questions
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