BASIC ELECTRONICS - OD1633 - LESSON 1/TASK 2
Another important relationship may be seen by studying figure 17. Thus far,
power has been calculated with voltage and current (P2 = E x I), and with
voltage and resistance
FIGURE 17.
GRAPH OF POWER RELATED TO CHANGING CURRENT
Referring to figure 16 on page 33, note that power also varies as the square
of current, just as it does with voltage. Thus, another formula for power,
with current and resistance as its factors is P = I2R. This can be proved
by:
Since:
E=IxR
By substitution in:
P=ExI
You get:
P=IxRxI
Or:
P= I x I x R
p = I2R
Therefore:
Up to this point, four of the most important electrical quantities have been
discussed. These are voltage (E), current (I), resistance (R), and
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