BASIC ELECTRONICS - OD1633 - LESSON 1/TASK 2
and
P=ExI
P = 2 volts x 1 ampere
P = 2 watts
When E is increased to 3 volts:
and
P=ExI
P = 3 volts x 1.5 amperes
P = 4.5 watts
You should notice that when the voltage was increased to 2 volts, the power
increased from .5 watts to 2 watts or 4 times. When the voltage increased
to 3 volts, the power increased to 4.5 watts or 9 times. This shows that if
the resistance in a circuit is held constant, the power varies directly with
the square of the voltage.
Another way of proving that power varies as the square of the voltage when
resistance is held constant is:
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