Transcript Power Definition of Power Unit of Power

Power
Definition of Power
Power is the amount of energy used per unit
time
Unit of Power
In electrical circuits, the most common unit for
power is the Watt :1 watt (W) = 1 joule/second
EGR 101
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Calculation of Power
J
P  
s
J
V  
C
C
I  
s
J C J
V I  
  P 
C s s
P  VI
EGR 101
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Calculation of Power (continued)
P  VI
V  IR
P  ( IR )( I )  I R
2
V
I
R
V  V
P  (V )  
R R
2
EGR 101
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3 Ways To Calculate Power
P  VI
Voltage and Current are known
PI R
Current and Resistance are known
2
2
V
P
R
Voltage and Resistance are known
EGR 101
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