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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