1. A parallel circuit with two bulbs Electricity model A series circuit with two bulbs Introducing the model Things to think about Contents

2. click here to close the switch switch off! Return to menu Model

3. click here to open the switch click here to increase voltage push! switch on! dim bulb Return to menu

4. click here to open the switch click here to decrease voltage push! switch on! bright bulb Return to menu

5. click here to close the switch switch off! Return to menu Series circuit

6. click here to open the switch push! switch on! very dim bulbs Return to menu Series circuit

7. click here to close the switch switch off! Return to menu Parallel circuit

8. click here to open the switch push! switch on! Return to menu Parallel circuit

9. The flow of electricity is called the current. Ammeters are used to measure this current (symbol ) Where in the circuit do you have to place an ammeter to measure the flow of electricity? The energy (or push) on the charges is called the voltage. Voltmeters are used to measure this voltage (symbol ) When the charges are in the bulb they transform their energy into thermal energy (heat) and light energy. Where in the circuit do you have to place a voltmeter to measure energy lost from the circuit in the bulb? Things to think about…1 Return to menu AV

10. Remember: the flow of electricity is called the current. Look back at the first circuit. What do you notice about the current along all four sides of the circuit? What do you notice about the current when the voltage is increased? Now look at the series circuit. What do you notice about the current when you put two bulbs together in series? Is the current larger or smaller when you put more bulbs in a circuit? Things to think about…2 Return to menu

11. Remember: the flow of electricity is called the current. Now look at the parallel circuit. What do you notice about the current when you put two bulbs together in parallel? Is the current after the first branch in the circuit larger or smaller than the current before the branch? What happens at the second branch in the circuit? In which circuit will… a)The cell run out of energy first? b)The cell run out of energy first? Why do you think this? Things to think about…3 Return to menu