HKDSE Physics Practice Paper with Answers | 14 questions, 60 minutes, 100 marks

2026-10-28

Practice paper · HKDSE Physics

HKDSE Physics practice paper: 10 multiple-choice questions in Section A and 4 structured questions in Section B, 60 minutes for 100 marks, covering mechanics, waves, electricity and heat, with full worked answers, marking notes and printable PDFs.

Download　Question paper PDF　|　Answer key PDF

Paper details　Level: S6 (HKDSE) | Subject: Physics | Time: 60 minutes | Total: 100 marks | Questions: 14

Section A: Multiple choice (20 marks)

1. Two marks each. Choose the best answer.

#	Question	Answer and marking notes
1	A car accelerates uniformly from rest to 20 m s⁻¹ in 8 s. What is its acceleration?	a = (v – u)/t = (20 – 0)/8 = 2.5 m s⁻². (2 marks)
2	How far does the car travel in those 8 s?	s = ½(u + v)t = ½(0 + 20)(8) = 80 m. (2 marks)
3	A ball is dropped from 45 m (g = 10 m s⁻², no air resistance). How long does it take to reach the ground?	s = ½gt² → 45 = ½(10)t² → t = 3 s. (2 marks)
4	At what speed does the ball reach the ground?	v = gt = 10 × 3 = 30 m s⁻¹. (2 marks)
5	A 1200 kg car accelerates at 2.5 m s⁻² against 500 N of friction. What is the driving force?	F = ma + f = 1200 × 2.5 + 500 = 3500 N. (2 marks; 3000 N alone earns 1 mark.)
6	A sound wave travels at 340 m s⁻¹ with a frequency of 250 Hz. What is its wavelength?	v = fλ → λ = 340/250 = 1.36 m. (2 marks)
7	Light passes from air into water (refractive index 1.33) at an angle of incidence of 30°. Which statement is correct?	The angle of refraction is less than 30°: the ray bends towards the normal because water is optically denser than air. (2 marks)
8	A 6 Ω and a 3 Ω resistor are connected in series to a 12 V supply. What is the current?	R = 6 + 3 = 9 Ω; I = V/R = 12/9 ≈ 1.33 A. (2 marks)
9	What is the equivalent resistance of a 6 Ω and a 3 Ω resistor in parallel?	1/R = 1/6 + 1/3 = 1/2 → R = 2 Ω. (2 marks)
10	A radioisotope has a half-life of 5 days. How much of an 80 g sample remains after 15 days?	15/5 = 3 half-lives; 80 ÷ 2³ = 10 g. (2 marks)

Section B: Structured questions (80 marks)

2. Answer all questions. Show your working and units.

#	Question	Answer and marking notes
11	A 70 kg person stands on a scale inside a lift (g = 10 m s⁻²). (a) What does the scale read when the lift is at rest? (b) When it accelerates upwards at 2 m s⁻²? (c) When it accelerates downwards at 2 m s⁻²? (20 marks)	(a) N = mg = 70 × 10 = 700 N. (6 marks) (b) N = m(g + a) = 70 × (10 + 2) = 840 N: the scale must also supply the upward acceleration. (7 marks) (c) N = m(g − a) = 70 × (10 − 2) = 560 N: the net force is downwards, so the reading falls. (7 marks)
12	A 2 kg ball slides from rest down a slope from a height of 5 m (g = 10 m s⁻²). (a) How much potential energy does it lose on reaching the ground? (b) What is its speed at the bottom if friction is ignored? (c) What is its speed if friction removes 40 J? (20 marks)	(a) ΔPE = mgh = 2 × 10 × 5 = 100 J. (6 marks) (b) ½mv² = 100 → v = √(2 × 100/2) = 10 m s⁻¹. (7 marks) (c) KE = 100 − 40 = 60 J → v = √(2 × 60/2) = 7.75 m s⁻¹ (√60). (7 marks)
13	A 12 V supply is connected to two 4 Ω resistors in parallel, and this combination is in series with a 2 Ω resistor. (a) What is the equivalent resistance of the circuit? (b) What is the total current? (c) What current flows in each 4 Ω resistor? (20 marks)	(a) Parallel part: (4 × 4)/(4 + 4) = 2 Ω; R = 2 + 2 = 4 Ω. (6 marks) (b) I = V/R = 12/4 = 3 A. (7 marks) (c) Voltage across the parallel part = 3 × 2 = 6 V; current in each 4 Ω branch = 6/4 = 1.5 A. (7 marks; 3 A scores 0.)
14	0.5 kg of water is heated from 20 °C to 80 °C (specific heat capacity 4200 J kg⁻¹ K⁻¹). (a) How much energy is absorbed? (b) How long should a 1000 W heater take? (c) Give one reason why the real time is longer. (20 marks)	(a) E = mcΔT = 0.5 × 4200 × 60 = 126000 J = 126 kJ. (7 marks) (b) t = E/P = 126000/1000 = 126 s. (7 marks) (c) Any one: heat is lost to the surroundings, the container absorbs heat, or evaporation carries heat away. (6 marks)

Find a tutor — free

A TutorZone practice paper; original questions and passages, not publisher material.