4ELEC-10

Outcomes

• Pupils can explain why electrical current can heat things up and identify where this is used in the home

Specification References

• 2.4 know some of the different ways in which electrical heating is used in a variety of domestic contexts
• 2.5 understand that a current in a resistor results in the electrical transfer of energy and an increase in temperature

Starter

Start with a few calculations using last lessons new equations (P=E/t, P=IV and E=IVT)

Main Body of Lesson

Class discussion, where do we use electricity to heat things up? Can also identify where we get heating where we don't want it. Can run some current through different thicknesses of wire and observe with the IR-camera. Pupils need to be able to explain the temperature increase in terms of KE transfer from the electrons to the lattice leading to more vibrations of the lattice and therefore greater temperature.

Plenary

• Have pupils explain how bulbs work
• Could wrap some wire around a splint and see if it will get hot enough to char or burn.

Additional Information

Resources Required

A selection of wires (possibly the resistance wire board), power supply, IR camera. Could also use resistors.

Safety/Hazards

Wires will get hot.