This final module quiz samples the full arc of Module 3: wave behaviour, sound, light, and thermodynamics. Treat it as the final consolidation check after the three checkpoints and the full lesson sequence.
Module Assessment
1. Which wave can travel through a vacuum?
2. If amplitude doubles, wave intensity becomes:
3. During refraction of a wave into a new medium, which quantity always stays the same?
4. In a standing wave, particles on opposite sides of a node move:
5. Two notes of 500 Hz and 506 Hz played together produce a beat frequency of:
6. A convex mirror typically forms an image that is:
7. Total internal reflection occurs when light travels:
8. Temperature is best understood as:
9. During a phase change at constant heating rate, a flat section on a heating curve means:
10. Which heat-transfer mode does not require a medium?
11. Explain why the bell-jar experiment supports the claim that sound is a mechanical wave. 3 MARKS
12. Light enters glass of refractive index 1.50 from air at 30°. Find the angle of refraction. 3 MARKS
13. Calculate the energy required to raise 1.2 kg of water by 8°C. Use $c = 4180\ \text{J/kg·K}$. 4 MARKS
14. Evaluate the statement “sound and light are basically the same because both are waves.” Include one similarity and one important difference. 4 MARKS
1. D — visible light is electromagnetic and can travel through vacuum.
2. B — intensity depends on amplitude squared.
3. A — frequency stays fixed across a boundary.
4. C — particles across a node are in antiphase.
5. D — beat frequency is $|500 - 506| = 6$ Hz.
6. B — convex mirrors produce virtual, upright, reduced images.
7. C — TIR needs denser-to-less-dense travel above the critical angle.
8. A — temperature measures average kinetic energy per particle.
9. D — the flat region represents latent heat for a phase change.
10. B — radiation does not need a medium.
Q11 (3 marks): In the bell-jar experiment, the source keeps vibrating while the sound fades as air is removed. This shows that sound needs a medium to travel. Because it requires particles in matter, sound is a mechanical wave.
Q12 (3 marks): Use $n_1 \sin \theta_1 = n_2 \sin \theta_2$. So $1.00 \times \sin 30^\circ = 1.50 \sin \theta_2$. Therefore $0.5 = 1.50 \sin \theta_2$, so $\sin \theta_2 = 0.333...$ and $\theta_2 \approx 19.5^\circ$.
Q13 (4 marks): $Q = mc\Delta T = 1.2 \times 4180 \times 8 = 40128\ \text{J}$, which is about $4.01 \times 10^4$ J.
Q14 (4 marks): The statement is partly true because both sound and light show wave behaviours such as reflection, refraction, diffraction, and interference. However, they are not the same kind of wave. Sound is mechanical and requires a medium, while light is electromagnetic and can travel through vacuum.
Tick when you have finished the quiz and checked the answers.