Fuse Selection Lab

Fuse Selection Lab is a free interactive simulation for GCSE Physics (Edexcel IGCSE 4PH1, spec points 2.2, 2.4). Students read an appliance's rating plate, work out its operating current, and pick the 3 A, 5 A or 13 A fuse that protects it, with feedback on every choice. No login required.

Aim: To practise choosing the correct fuse for a mains appliance using its rating plate.

Appliance

Step 1 — Operating Current

Work out the current this appliance draws in normal use, then type it in.

Step 2 — Choose a Fuse

Session Score

0 correct out of 0 attempted

Part A — Finding the correct fuse

  1. Choose an appliance from the dropdown, or click New Appliance for a random one, and read the values on its rating plate.
  2. Use the power and voltage on the plate to work out the operating current (current = power ÷ voltage), type your answer into the box and click Check Current.
  3. Once your current is accepted, click the fuse rating you think protects this appliance and read the feedback.
  4. Repeat for at least four different appliances, including the lowest-power and the highest-power appliance in the list. How does the correct fuse rating relate to the size of the operating current?

Part B — Testing fuses that are too small or too large

  1. Load a new appliance and work out and accept its operating current as before, but do not click the correct fuse yet.
  2. Click a fuse rating that is smaller than the operating current and read the feedback message.
  3. Now click a fuse rating that is larger than the operating current — and larger than the correct rating, if there is one — and read the feedback message.
  4. Finally click the correct fuse. Using what you found in the last three steps, explain why a fuse rated too small is a nuisance rather than a safety risk, while a fuse rated too large is genuinely dangerous even though it never blows.