1. Current
We can measure the amount of current using an Ammeter. A
Current is measured in Amperes (A)

2. Electrons, Charge & Current
Electrons - negative charge.
Charge (Q) is measured in coulombs (C) C = 6x1018 e
What is the charge on ONE electron?
1e = 1.6 x10-19 C
The movement of electric charges is called current (I), unit (A).
The size of electric current (I) is the rate at which charge flows
Time t q
note 1A = 1Cs-1

4. In Series

5. Current & Ammeters Investigation
Place an Ammeter at various point in a circuit with one bulb and measure the current flow
Repeat with two bulbs in series
Repeat with two bulbs in parallel 1. 2.
For each task draw a circuit and record the current values at each point (either side of a light bulb) measured in the circuit. 3.
What can you conclude about
Current in S & P circuits ???

6. Dial at 10A
0 to 10 A
COM
Ammeter

8. Voltage
Voltage is a measure of how much ________ is carried or provided by the electrons.
Voltage is measured in Volts (V) , using a Voltmeter. V

9. Voltage measures the amount of energy carried by a certain amount of charge
Energy, measured in Joules (J)
Voltage, measured in Volts (V)
Charge, measured in Coulombs (C)

10. In Parallel

11. Dial at 20V
VΩmA
COM
Voltmeter

12. What can you conclude about Voltage in S & P circuits ???
Voltage investigation
Investigation:
Set up a circuit with one bulb and measure the Voltage drop across the bulb (V1) and power supply (Vs)
2. Repeat with two bulbs in series, measure V1 V2 and Vs
3. Repeat with two bulbs in parallel, measure V1 V2 and Vs
For each task draw a circuit and record the voltage values for each component, then comment on your observations (ie bulb brightness).
What can you conclude about Voltage in S & P circuits ???

13. Q1. What will happened to the brightness of the bulb when you add more batteries? Explain why
Q2. What happens to the bulb in circuit D? Explain why.

14. The Fiddly Stuff!

16. V & I in a (series) circuit