Questions
1. Explain: what a semiconductor diode does.
A diode lets current flow through it in one direction only. This one-way behaviour is used to turn alternating current into direct current, called rectification.
2. Explain: how a transistor acts as a switch.
A small current into the base of a transistor lets a much larger current flow through the main circuit. Removing the small current switches the large one off, so the transistor works as an electronic switch.
3. Explain: what doping does to a semiconductor.
Adding a tiny amount of impurity to pure silicon greatly increases its ability to conduct. Depending on the impurity, it forms n-type or p-type material, the building blocks of diodes and transistors.
4. Define p-type semiconductor.
A semiconductor doped so that positive holes are the majority charge carriers.
5. Define semiconductor diode.
A component made from a p-n junction that allows current to flow in one direction only.
6. Define rectification.
The process of converting alternating current into direct current, usually using diodes.
7. Define transistor.
A semiconductor device with three terminals used to amplify signals or to act as an electronic switch.
8. Define light-emitting diode (led).
A semiconductor diode that emits light when a current flows through it in the forward direction.
9. Define electron.
A stable subatomic particle carrying a negative electric charge, found orbiting the nucleus of an atom.
Marking yourself
- Calculation: formula written, values substituted with units, final answer with unit and sensible significant figures.
- Variables: manipulated = what you change; responding = what you measure; constant = what you keep the same.
- Definition: one sentence, correct physical quantity, correct unit.
Exam tip
More Electronics resources
- Chapter overview: Electronics
- Revision Notes
- Common Mistakes
- Paper 2 Answering Guide
- Paper 3 Guide
- Key Terms
Source: DSKP KSSM Physics Form 4 and 5 (Versi English), Sijil Pelajaran Malaysia: Format Pentaksiran mulai 2021, Fizik (4531) (Bahagian Pembangunan Kurikulum (BPK), KPM)