CALCULATING WITH OHM'S LAW
A. When Volts and OHMS are known:
|
Amperes =
|
Volts
---------
OHMS
|
of I =
|
E
-----
R
|
Example: Find the current of a 120 volt circuit with a resistance of 60 OHMS.
|
I =
|
E
-----
R
|
=
|
120
------
60
|
= 2 Amperes
|
B. When Watts and Volts are known:
|
Amperes =
|
Watts
----------
Volts
|
or I =
|
P
------
E
|
Example: A 120 Volt Circuit has a 1440 Watt Load. Determine the current.
|
I =
|
P
---------
E
|
=
|
1440
---------
120
|
=12 Amperes
|
C. When OHMS and Watts are known:
Example: A circuit consumes 625 watts through a 12.75 OHM resistor. Determine the current.
Notes:
A. One Electrical Horsepower = 746 watts. Electric Motors are rated in horsepower.
B. One kilowatt = 1000 watts. Generators are rated in kilowatts.