VIDEO http www youtube comwatch vE 27 XDNf

VIDEO http: //www. youtube. com/watch? v=E 27 XDNf 2 cxc

OHMS LAW

What is ohms law? Ohm’s Law explains the relationship between voltage (V ), current (I) and resistance (R) Used by electricians, automotive technicians, stereo installers

VOLTAGE (V) It is the push or pressure behind current flow through a circuit. Measured in (V) volts.

How you should be thinking about electric circuits: Voltage: a force that pushes the current through the circuit (in this picture it would be equivalent to gravity)

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

How you should be thinking about electric circuits: Current: the actual “substance” that is flowing through the wires of the circuit (electrons!)

RESISTANCE Resistance to the flow of the current. Measured in Ohms

How you should be thinking about electric circuits: Resistance: friction that impedes flow of current through the circuit (rocks in the river)

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.

Part 2 http: //www. youtube. com/watch? v=e. Z 9 Xk 0 Lln 5 Y&feature=related Stop at 1 Min mark

How do we used Ohms law

V = Ix. R I=V R R=V I

How do calculate? Battery voltage is 12 V Resistance 2 Ohm What is the Current?

How to calculate? Voltage is 12 V Current is 4 Amps What is the Resistance? ____Ohms?

What can we use to measure? Multi meters/ DVOM

Resistors Why do we need resistors To decrease the amount of voltage applied to a component The value of the resistor is marked on the body using coloured rings