4-ELC-02

Outcomes

• Pupils can explain how changing resistance changes current
• Pupils can link voltage, current and resitance

Specification References

• 2.12 describe the qualitative effect of changing resistance on the circuit on the current in a circuit
• 2.15 recall and use the relationship between voltage current and reistance V=IR

Starter

Give pupils white boards ask them to draw a standard test circuit - i.e. a circuit which they can use to test any standard component (e.g. a resistor)

Pupils should include a power supply, ammeter (in series), a test component (e.g. a resistor), voltmeter (in parallel around the test component).

For bonus marks ask them to identify the positive terminal of their supply

Main Body of Lesson

• Invesitgate three different resistors (10 ohm, 20 ohm and 30 ohm), plot an I-V graph, find the gradient, make conclusions
• Make a 10 ohm resistor - classic. Give pupils a length of wire and ask them to make a 10 ohm resistor - either use trial and error (quick method) or plot graph of resistance against length and read off ideal value.

Additional Information

Resources Required

12x the following:

• 5V power supplies
• 10 ohm resistor
• 20 ohm resistor
• 30 ohm resistor
• simple ammeter
• simple voltmeter
• PASCO I-V sensor
• length of wire for 10 ohm resistor challenge
• wooden block to wind wire on
• 2 x croc clips