1. Ohm’s Law

2. Learning Goals  I will be able to use Ohm’s Law to solve for current, voltage and resistance.

3. Ohm’s Law  Recall:  Current (A): A measure of how fast electrons are moving in a circuit.  Potential Difference / Voltage (V): A measure of the electron “pressure” in a circuit.  Higher voltage means more charged particles.  As voltage increased, current increased.  Force of repulsion became greater.  Recall:  Current (A): A measure of how fast electrons are moving in a circuit.  Potential Difference / Voltage (V): A measure of the electron “pressure” in a circuit.  Higher voltage means more charged particles.  As voltage increased, current increased.  Force of repulsion became greater.

4. Ohm’s Law cont’d  Ohm’s law relates the voltage and current in a circuit to the resistance.  It is given by:  We can use this to analyze behavior in parts of circuits.  Ohm’s law relates the voltage and current in a circuit to the resistance.  It is given by:  We can use this to analyze behavior in parts of circuits. Where: R = Resistance (ohms) V = Voltage (V) I = Current (A) R V I

5. Example #1  A lamp has a current of 1.2 A flowing through it with a voltage of 6.0V. What is the resistance of the load?

6. Example #2  A coffee maker has a resistance of 20 Ω and a current of 5.0A when on. What is the voltage across the coffee maker?

7. Example #3  A 110 Ω resistor is connected to a power supply set at 12 V. Calculate the current going through the resistor.

8. Example #4  A toaster oven has a 24.0 Ω resistor that has 5.00 A of current going through it when the toaster is on. Calculate the potential difference across the resistor.

9. Learning Goals Revisted  I will be able to use Ohm’s Law to solve for current, voltage and resistance.

10. Please Complete  P570 #5,6,7,8