1. Ohm’s Law – The relationship between Current, Voltage and Resistance.

2. Starter
Decode the information from the sheet. Write the solution in your book.

3. Solution - Resistance
Electrons carry current around a circuit. Sometimes the electrons collide with the atoms that the wire is made out of. This is what causes resistance. There are more collisions in a long wire than a short wire and more in a thin wire than a thick one. This means the wire with the least resistance is a short thick one.

4. Ohm’s Law
Today we’re going to investigate the relationship between current and voltage.
We will carry out a practical where we will change the voltage of our power supply and measure the resulting change in current.

5. Make a prediction!
Write the title “Investigating Ohm’s Law” in your book…this is a lab report!
Make a sub-heading “Prediction”
Under this you need to make your own prediction – what do you think will happen in the experiment? How do you think the current will change as we increase the voltage?

6. Equipment list Make a new sub-heading “Equipment list”
Make a list using bullet-points of the equipment we will use:
Power supply
Connecting wires
1 bulb
1 variable resistor
2 multimeters
1 switch
Write a short note to describe what each piece of equipment is used for.

7. Circuit diagram Make a sub-heading “Circuit Diagram”
Draw a circuit diagram:
5 – 7 V A V

8. Procedure Make a sub-heading “Procedure”
Set up the circuit as it is in the circuit diagram without the meters. The switch should be open and voltage set to zero.
Add a multimeter in series to act as an ammeter. Set it to the 10 A setting using the “COM” and “10A” connections.
Set the other multimeter to the 20 V setting.
Plug connecting wires into “COM” and “V Ω mA” and connect it in parallel across the bulb.
Close the switch and increase the voltage to 5 V
Record the current value.
Repeat the experiment increasing the voltage each time by 0.5 V until you reach 7 V
Repeat the full experiment.

9. Results Table – Make a sub-heading!! 
Voltage (V)
Test 1 (A)
Test 2
(A)
Average Current (A)
5.00
5.50
6.00
6.50
7.00

10. Results Table – Make a sub-heading!! 
Voltage (V)
Test 1 (mA)
Test 2 (mA)
Average Current (mA)
0.50 22 18
1.00 40
1.50 59 61
2.00 81 79
2.50
100
3.00
122
118

11. Make a sub-heading “Graph”
We will plot a graph with “Voltage (V)” on the x- axis and “Average Current (A)” on the y-axis.