1. Measuring Voltage and Current Aims Know the units of voltage and current Know how to measure voltage and current

2. Circuit Symbols A. B. C. D. E. F. G. H. I. Ammeter Motor Voltmeter Bulb Cell Battery Buzzer Switch closed Switch open

3. Draw a Circuit Diagram for the Apparatus Below

6. Measuring Current. The unit of measure for current is the "amp" which has the symbol A. We measure the current using a device called an ammeter. In a circuit this is given the symbol When measuring the current through a component, the ammeter is always connected in series (in the same loop) with that component. AA A

7. Measuring Voltage. When measuring the voltage across a component, the voltmeter is always connected in parallel with (or across) the component. V2V2 V1V1 We measure the voltage using a device called an voltmeter. In a circuit this is given the symbol V The voltage supplied by the battery is shared between all the components in a series circuit This is still a SERIES circuit.

8. Series Circuit Animation

9. 1. Set up the circuit as shown above. 2.Connect the voltmeter across the power supply and measure the supply voltage. 3.Then connect the voltmeter across the resistance (R) and measure this voltage. Experiment: Measuring Voltage R V V Circuit 1

10. Basic ideas… Electric current is when electrons start to flow around a circuit. We use an _________ to measure it and it is measured in ____. Voltage is how big the push on the electrons is. We use a ________ to measure it and it is measured in ______, a unit named after Volta. Resistance is anything that resists an electric current. It is measured in _____.” (Words: volts, amps, ohms, voltage, ammeter, voltmeter)

11. Energy changes To describe an energy change for a light bulb we need to do 3 steps: Electricity Light + heat 1) Write down the starting energy: 3) Write down what energy types are given out: 2) Draw an arrow What are the energy changes for the following…? 1)An electric fire 2)A rock about to drop 3)An arrow about to be fired

12. Electrical Energy Consider a simple circuit: Words – electrical (x2), light, chemical The job of the battery is to convert ______ energy into _________ energy… The job of the bulb is to convert the _________ energy it receives from the battery into ______ energy.

13. Electrical Energy Energy Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit.

14. Electrical Energy Energy Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit.

15. Electrical Energy Hi. I’m Ernie Electron and I’m going to show you how I get energy around a circuit. Energy