2026 WAEC GCE Physics 3
Alternative to Practical Work: Questions, Answers and Marking Guide
Original Practice Examination Only
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Important Notice
This is an original WAEC GCE-style Physics 3 practice examination for revision. It is not an official WAEC paper, does not reproduce the actual 2026 examination, and does not predict or claim to represent questions that will appear. The numerical data and experimental situations are independently created.
2026 WAEC Physics Paper Information
WAEC’s published 2026 Nigeria timetable lists Physics 3 (Practical), Alternative A, under SC5123/A and Alternative B under SC5123/B. Each is scheduled for 2 hours 45 minutes.
Instructions
- Answer all questions.
- Show calculations clearly.
- Use appropriate SI units and significant figures.
- Label graphs and axes correctly.
- State sensible experimental conclusions.
- This is a practice paper only.
1. Simple Pendulum
A student investigates the relationship between the length L of a simple pendulum and its period T.
L (m): 0.40, 0.50, 0.60, 0.70, 0.80
Time for 20 oscillations t (s): 25.4, 28.5, 31.1, 33.5, 35.9
(a) Calculate T for each length. (b) Calculate T². (c) Plot T² against L. (d) Determine the gradient. (e) State the relationship. (f) Give two precautions.
Suggested Answer / Marking Points
(a) T=t/20: 1.270, 1.425, 1.555, 1.675 and 1.795 s.
(b) T²: approximately 1.613, 2.031, 2.418, 2.806 and 3.222 s².
(c) A graph of T² against L should be approximately linear.
(d) Gradient using the end readings is about (3.22-1.61)/(0.80-0.40)=4.0 s² m⁻¹.
(e) T² is directly proportional to L for a simple pendulum of small amplitude.
(f) Keep amplitude small; measure length to the centre of the bob; release without pushing; avoid parallax; time several oscillations.
2. Hooke’s Law
A spring is loaded gradually.
Force F (N): 0.5, 1.0, 1.5, 2.0, 2.5
Extension x (cm): 1.1, 2.2, 3.3, 4.4, 5.5
(a) Plot x against F. (b) Determine the spring constant. (c) State the law. (d) Give two reasons not to exceed the elastic limit. (e) State one reading precaution.
Suggested Answer / Marking Points
(a) The graph is a straight line close to the origin.
(b) At 2.0 N, x=0.044 m. k=F/x=2.0/0.044≈45.5 N m⁻¹.
(c) Within the elastic limit, extension is directly proportional to applied force.
(d) Overloading may permanently deform the spring and make later readings unreliable.
(e) Read the ruler at eye level to reduce parallax.
3. Ohm’s Law
A resistor gives the following readings.
I (A): 0.10, 0.20, 0.30, 0.40, 0.50
V (V): 1.2, 2.4, 3.6, 4.8, 6.0
(a) Plot V against I. (b) Determine resistance. (c) State the relationship. (d) Why open the switch between readings? (e) Name the instruments for current and voltage.
Suggested Answer / Marking Points
(a) Plot V vertically against I horizontally; a straight line through the origin is expected.
(b) R=V/I=6.0/0.50=12 Ω.
(c) For a constant-temperature ohmic conductor, V is directly proportional to I.
(d) It reduces heating and helps keep temperature approximately constant.
(e) Ammeter and voltmeter.
4. Convex Lens
A convex lens forms a sharp image on a screen.
u (cm): 20, 25, 30, 35, 40
v (cm): 60.0, 50.0, 43.0, 38.5, 35.0
(a) For u=20 cm and v=60 cm, calculate f using 1/f=1/u+1/v.
(b) For u=25 cm and v=50 cm, calculate f.
(c) State two precautions. (d) How is a sharp image located? (e) Why repeat readings?
Suggested Answer / Marking Points
(a) 1/f=1/20+1/60, so f=15.0 cm.
(b) 1/f=1/25+1/50, so f≈16.7 cm.
(c) Keep object, lens and screen at the same height; avoid parallax; keep the lens vertical.
(d) Move the screen until the image is sharply defined.
(e) Repetition improves reliability and helps reveal anomalous readings.
5. Density of a Solid
A metal block has dimensions 5.0 cm × 4.0 cm × 2.0 cm and mass 320 g.
(a) Calculate volume. (b) Calculate density in g cm⁻³. (c) Convert to kg m⁻³.
(d) State one advantage of repeated measurements. (e) How would you determine the volume of a suitable irregular solid?
Suggested Answer / Marking Points
(a) V=5.0×4.0×2.0=40.0 cm³.
(b) Density=320/40=8.0 g cm⁻³.
(c) 8.0 g cm⁻³=8,000 kg m⁻³.
(d) It reduces random error and helps identify anomalous readings.
(e) Use water displacement in a measuring cylinder or displacement can, where appropriate.
6. Principle of Moments
A uniform metre rule balances on a knife edge at 50 cm. A 200 g mass hangs at 30 cm and a second mass at 70 cm restores balance. Take g=10 m s⁻².
(a) Calculate the weight of the 200 g mass. (b) Calculate its moment about the pivot. (c) Calculate the second mass. (d) State the principle. (e) Give two precautions.
Suggested Answer / Marking Points
(a) 200 g=0.200 kg, so W=mg=2.0 N.
(b) Distance=20 cm=0.20 m. Moment=2.0×0.20=0.40 N m.
(c) The other distance is also 0.20 m, so m×10×0.20=0.40; m=0.20 kg=200 g.
(d) For equilibrium, clockwise moment equals anticlockwise moment about the pivot.
(e) Keep the rule horizontal; use a stable pivot; read positions without parallax; allow the rule to settle.
General Marking Guide
- Tables: award marks for correct readings, headings and units.
- Graphs: award marks for labelled axes, units, suitable scale, accurate plotting, best-fit line and correct gradient.
- Calculations: award method marks when the correct formula and substitution are shown.
- Precautions: accept any scientifically valid precaution that reduces error or improves reliability.
- Conclusions: the conclusion must follow from the observed data.
- Alternative scientifically valid methods should receive credit where they achieve the stated objective.
Final Disclaimer
This document is a privately created educational practice resource. It is not issued by WAEC and must not be described as the actual 2026 WAEC GCE Physics 3 paper, leaked questions, or guaranteed examination questions.
Continue visiting EDUJECTS.com for verified examination updates, revision guides, past question analysis, and study materials throughout the 2026 examination season.
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