1. Ohm’s Law

2. Quantities of a Circuit
Voltage
– pushes the electrons
The ends of a battery are oppositely charged. This creates a force or the prime mover, pushing the electrons through the circuit.
Volts ,V
Voltage is measured in

3. Quantities of a Circuit.
Quantities of a Circuit
Current
– flows through circuits
The flow of electrons we call current which travels through closed circuits. ,A
Amperes
Current is measured in

4. Quantities of a Circuit
Resistance
– resists current flow
Devices in the circuit do work, which slows down (restricts) current. ,Ω
Ohms
Resistance is measured in

5. We will need to use our electric circuit symbols to diagram some circuits

6. V = I R OHM’S LAW (resistance in a circuit)
"For a given resistor at a particular temperature, the current is directly proportional to the applied voltage."
Georg Simon Ohm ( )
V = I R
Units: Volt/Amperes = ohm (Ω)

7. Example 1: The voltage of an electric heater is 80 V when there is a current of 6 A in the heater. What is the resistance of the heater?
Givens:
V1 = 80 V
I = 6 A R = ?
= 13.3 Ω
B. What is the current if the voltage is increased to 120V?
Givens:
V2 = 120 V
R = Ω
I = ?
= 9 A