1. oneone GTE-8A Objective: To use Ohm’s Law relationships to determine voltage, current, and resistance in simple circuits. Energy Note: How are current voltage, and resistance related ? Drill: 1. Get a new lab from the SET. 2. Complete Activity 1, #1 only. OHM’S LAW

2. oneone GTE-8A Current (I) : the continuous flow of electrons through a circuit units: amperes (A) Voltage (V): the force causing the flow of electrons units: volts (V) Resistance (R): anything that hinders the flow of electrons (current) units: ohms (Ω) HANDOUT OHM’S LAW

3. oneone GTE-8A Ohm’s Law provides the relationship between current, voltage and resistance. Ohm’s Law → Voltage = Current × Resistance Work with your neighbor to rewrite the Ohm’s Law formula in terms of the other 2 variables. Resistance = Voltage ÷ Current Current = Voltage ÷ Resistance OHM’S LAW

4. oneone GTE-8A Activity 3: Applying the Formulas A 12 volt circuit is used to operate a light. The resistance in the circuit is 2.5 Ω. What is the current going through the circuit? Current = Voltage ÷ Resistance Current = 12V ÷ 2.5Ω Current = 4.8A OHM’S LAW

5. oneone GTE-8A Activity 3: Applying the Formulas What is the voltage (electrical pressure) of a circuit with a current of 8.75 amps and a resistance of 9 Ω? Voltage = Current × Resistance Voltage = 8.75A × 9Ω Voltage = 78.75V OHM’S LAW

6. oneone GTE-8A Explain what happens to the current in a circuit that obeys Ohm’s Law if the resistance is doubled and the voltage remains the same. ELMO DEMO TRY THIS: Explain what happens to current in a circuit if voltage is tripled and resistance is cut in half. OHM’S LAW

7. oneone GTE-8A HOMEWORK: Ohm’s Law Practice Problem Sheet. Show all work. OHM’S LAW