1. OHM’S LAW INTRODUCING MOTOR VEHICLE ELECTRIC’S BY PAUL LANE
Original Power Point Created by Paul Lane
Modified by Georgia Agricultural Education Curriculum Office
June 2002

2. WHERE DID OHM’S LAW COME FROM?

3. OHM’S LAW
TO UNDERSTAND OHM’S LAW WE MUST
FIRST LEARN SOME SIMPLE ELECTRICAL
SYMBOLS:
SINGLE CELL
FUSE
SINGLE ACTION SWITCH
CAPACITOR
BULB
RESISTOR

4. ELECTRICAL SYMBOLS
ONE WAY DIODE
VARIABLE RESISTOR
EARTH
WIRES CROSSING
WIRES JOINING
IGNITION COIL
CONTACT POINT

5. OHM’S LAW
WHAT IS OHM’S LAW?
V= I  R
Where:
V = VOLTAGE
I = CURRENT
R = RESISTANCE
EXAMPLE:
A 12 VOLT BATTERY SUPPLIES POWER
TO A HEATED REAR WINDOW WHICH
HAS A RESISTANCE OF 18 OHM’S.
CALCULATE HOW MUCH CURRENT IS
FLOWING THROUGH THE HEATED
WINDOW.

6. V I R USING THIS SIMPLE TRIANGLE WE CAN SEE THAT: I = V R 12 I = 18
V = 12 VOLTS
R = 18 OHM’S
USING THIS SIMPLE TRIANGLE
WE CAN SEE THAT: V
I = V I R R 12
I = 18
I =
0.6 