Practical work: repairing hand-held power tools
The trigger switch of a drill that has been used a lot can fail: the tool stops and starts during work or the switch must be pressed hard to make the motor run. Before any check the tool’s plug must be pulled out of the socket; opening or touching a tool that is connected to power is forbidden. Such work is done only by the teacher or a qualified master, while pupils watch the sequence and learn the main rules. The body bolts are undone and the switch is taken out (carefully, because its parts may scatter), tested for continuity with a multimeter and cleaned of dust. If it cannot be repaired a new one is bought: it must match the old one in power rating, size and whether it has a reverse, so the old one is taken along as a sample. Wires are joined with a soldering iron (also done by the master), and the tool is tested only after it has been reassembled and its body closed.
Role play (no real tool): the “master” starts explaining the plan, and the “pupils” ask before each step “Is the plug out?” Then look at a picture of a multimeter and find its modes (DC voltage, AC voltage, resistance, current). Use a real multimeter only on a battery or low-voltage source, with the teacher.