2. Electrical Circuits Making Electricity Useful

3. Circuit Diagrams Electrical circuits can be shown in diagrams using symbols: 9.0V

4. Circuit Diagram Symbols: AC DC battery AC power supply DC power supply bulb resistor switch conductors (wires) A V voltmeter ammeter

5. Circuit Components: Ammeter – measures amount of current (I) Voltmeter – measures the amount of voltage (V) Add resistance (R) to a circuit (slows electricity) Batteries – add voltage/current to the circuit AC Power Supply – adds AC current to the circuit Switch – allows the electricity to be turned on/off A V AC

6. What will the Ammeter Read? (Find the amount of current (I)) A 8.0  24 V ? Ammeter measures current I = V ÷ R I = 24v ÷ 8.0A I = 3.0 A

7. Creating and Interpreting Circuit Diagrams: Draw the following circuit diagram: A circuit with a 9.0 v battery, an ammeter, and a 3.0  resistor. What will the ammeter read? (What amount of current is in the circuit?)

8. Circuit Diagram #1 9.0V A 3.0  I = V/R I = 9.0V/3.0  I = 3.0 A

9. Creating and Interpreting Circuit Diagrams: Draw a circuit with … AC power supply an ammeter a voltmeter 8.0  resistor If the ammeter reads 4.5 Amps, what will the voltmeter read?

10. Circuit Diagram #2: What will the voltmeter read? A 8.0  AC 4.5A V = IR V = (4.5A)(8.0  ) V = 36v V