OHMS LAW

Ohm’s Law

Voltage

Current

Resistance

Resistor

Circuit

Example

Quiz

What is ohms law?

Ohm’s Law explains the relationship between voltage (V or E), current (I) and resistance (R)

Used by electricians, automotive technicians, stereo installers

CURRENT

Current refers to the quantity/volume of electrical flow. Measured in Amps (A)

VOLTAGE (V)

It is the push or pressure behind current flow through a circuit, and is measured in (V) volts.

RESISTANCE

Resistance to the flow of the current. Measured in Ohms

Chart

General Rule.

1. Assuming the resistance does not change: As voltage increases, current increases. As voltage decreases, current decreases.

2. Assuming the voltage does not change: As resistance increases, current decreases. As resistance decreases, current increases.

How do we used Ohms law

• V (E) = I x R

• I = V R

R = V I

How do calculate?

Battery voltage is 12VCurrent is Amp ?Resistance 2 Ohm

How to calculate?

Voltage is 12VCurrent is 4 AmpsResistance Ohms ?

What can we use to measure?

Multi meters/ DVOM

Resistors

Why do we need resistorsTo decrease the amount of voltage

applied to a component The value of the resistor is marked on the

body using coloured rings

Resistors

Resistor color chart

Load

What is a loadIt is a any electric load on a circuit that

does work.Example: Power windows, light bulbs,

motors.

Different types of circuitSeries circuit : One pathway for current to flow.Example: Old Christmas lights

Parallel Circuit More then one path way for current to flow.Used in most electrical vehicle circuits.

Series and Parallel Circuits

12

Parallel resistance circuit

What it looks like

1997 Headlight circuit

QUIZ

QUIZ

What is Voltage?What is Current?What is Resistance?What are wiring diagrams?What are the different circuits and there characteristics?