Grade 12 · Physical Sciences · Physics, Paper 1 · CAPS
Photoelectric Effect and Spectra – Grade 12 Physical Sciences (Physics, Paper 1)
What Photoelectric Effect covers, how it is examined in Physical Sciences Paper 1 (Physics), the 4 sections to study and how long it takes – plus live online lessons when you get stuck.
- Study sections
- 4
- Exam-style questions
- 10
- Marks of practice
- 95
- Study time
- ≈ 4 h 00 min
What it covers
This topic shows why light must sometimes be treated as a stream of particles. In the photoelectric effect light energy arrives in photons with energy E = hf: you use the work function, threshold frequency and photoelectric equation to find how fast the ejected electrons can move, and explain why brighter light releases more electrons but not faster ones. It also covers line spectra – bright lines given off by hot gases and dark lines where light is absorbed – which come from electrons jumping between energy levels.
How it is examined
- Paper
- Physical Sciences Paper 1 (Physics) – Friday 30 October 2026, 09:00 (3 hours, 150 marks)
- Weighting
- Matter & materials ≈ 15/150 (optical phenomena typically ≈ 10–13 marks, plus one or two MCQs)
- Questions
- In a typical paper you will find it in the last question (Question 10 or 11) of Physical Sciences Paper 1 (Physics), with multiple-choice items in Question 1 as well.
Question numbers and mark splits are typical, not fixed – they vary a little from year to year.
Sections to study
- Photons and the particle nature of light25 min
- The photoelectric effect and the photoelectric equation35 min
- Intensity vs frequency; E_k(max) against f graphs30 min
- Emission and absorption spectra25 min
Study time
| Notes and worked examples4 sections | 1 h 55 min |
|---|---|
| Exam-style questions10 questions · 95 marks × 1,2 min per mark | 1 h 55 min |
| Topic quiz | 10 min |
| Total | ≈ 4 h 00 min |
Physical Sciences Paper 1 (Physics) is written on Friday 30 October 2026 at 09:00.
What you get in the portal
- 10 exam-style questions on Photoelectric Effect (95 marks in total), each with a full marking memo
- Worked examples with diagrams and step-by-step calculations for each of the 4 sections
- Tutor notes added to sections and questions – for the whole class or just for you
- A topic quiz, mock papers and a study plan that counts down to Physical Sciences Paper 1 (Physics)
Notes, worked examples, questions and memos open once the tutor approves your account – usually with your first confirmed lesson.
Stuck on Photoelectric Effect? Book a one-on-one lesson.
R250 per hour – 60, 90 or 120 minutes, online from anywhere in South Africa. Pick Photoelectric Effect as your topic; you pay by EFT only after the tutor confirms.
Related Physics P1 topics
- Newton's Laws and Applications
- Momentum and Impulse
- Vertical Projectile Motion (1D)
- Work, Energy and Power
All Grade 12 Physical Sciences topics, weighting and study time
Questions about Photoelectric Effect
How many marks is Photoelectric Effect worth in the matric exam?
In Physical Sciences Paper 1 (Physics) (3 hours, 150 marks) the usual weighting is: Matter & materials ≈ 15/150 (optical phenomena typically ≈ 10–13 marks, plus one or two MCQs). In a typical paper you will find it in the last question (Question 10 or 11) of Physical Sciences Paper 1 (Physics), with multiple-choice items in Question 1 as well. The exact marks change a little from year to year.
How long does it take to study Photoelectric Effect?
About 4 h 00 min: 1 h 55 min for the notes and worked examples in its 4 sections, 1 h 55 min for the 10 exam-style questions (95 marks) at exam pace of 1,2 minutes per mark, and a 10-minute quiz.
When is the Physical Sciences Paper 1 (Physics) exam in 2026?
Physical Sciences Paper 1 (Physics) is written on Friday 30 October 2026 at 09:00 and lasts 3 hours (150 marks), according to the DBE’s 2026 NSC timetable. Confirm the date with your school, because the DBE can amend the timetable.
Can I get online lessons for Photoelectric Effect?
Yes. Create a free account in the Adventuity portal, request a one-on-one online lesson of 60, 90 or 120 minutes (or a seat in a group class) and choose Photoelectric Effect as your topic. You pay by EFT only after the tutor confirms the booking.