Waves, Light & Sound Quiz

1. What is the difference between a transverse wave and a longitudinal wave?

1. In transverse waves, oscillations are perpendicular to the direction of travel; in longitudinal waves, they are parallel
2. Longitudinal waves cannot travel through solids
3. Transverse waves require a medium; longitudinal waves do not
4. Transverse waves travel faster

2. What is the speed of sound in air at room temperature?

1. 150 m/s
2. 3,000 m/s
3. 300,000 km/s
4. 340 m/s

3. What is refraction?

1. The absorption of wave energy
2. The bending of a wave as it passes from one medium to another due to a change in speed
3. The bouncing of a wave off a surface
4. The spreading of waves around obstacles

4. What is the order of the electromagnetic spectrum from longest to shortest wavelength?

1. Gamma, X-ray, ultraviolet, visible, infrared, microwave, radio
2. Radio, infrared, X-ray, visible, microwave, ultraviolet, gamma
3. Radio, microwave, infrared, visible, ultraviolet, X-ray, gamma
4. Visible, radio, X-ray, microwave, infrared, ultraviolet, gamma

5. What is the law of reflection?

1. The angle of incidence equals the angle of reflection
2. The angle of incidence equals the angle of refraction
3. The reflected wave has less energy than the incident wave
4. Waves always reflect at 90°

6. What type of electromagnetic radiation is used in mobile phone communications?

1. Infrared
2. Microwaves
3. Ultraviolet
4. X-rays

7. What is the frequency of a wave that has a speed of 300 m/s and a wavelength of 0.5 m?

1. 150 Hz
2. 300 Hz
3. 60 Hz
4. 600 Hz

8. What is diffraction?

1. The bending of waves around corners or through gaps
2. The change in frequency when a source moves
3. The reflection of waves
4. The splitting of white light into colours

9. Which colour of visible light has the highest frequency?

1. Green
2. Red
3. Violet
4. Yellow

10. What is the Doppler effect?

1. The absorption of light by matter
2. The apparent change in frequency of a wave when the source or observer is moving
3. The bending of light through a prism
4. The splitting of sound into echoes

11. What is an echo?

1. A reflected sound wave heard after a short delay
2. Interference between two sound waves
3. Sound absorbed by soft surfaces
4. Sound that travels faster than normal

12. What is total internal reflection?

1. When a wave reflects off a flat mirror
2. When all light is absorbed by a surface
3. When light hits a boundary at or beyond the critical angle and reflects entirely back into the medium
4. When light passes straight through without bending

13. What does a converging (convex) lens do to parallel rays of light?

1. Absorbs them
2. Brings them together at a focal point
3. Reflects them back
4. Spreads them apart

14. What causes the white light from the Sun to split into a rainbow of colours?

1. Absorption and re-emission
2. Diffraction around clouds
3. Reflection off water droplets
4. Refraction — different wavelengths of light slow down by different amounts in water/glass

15. What is ultrasound?

1. Electromagnetic waves used in hospitals
2. Sound that travels faster than light
3. Sound with frequency above 20,000 Hz, beyond human hearing
4. Very loud sound

16. What is the amplitude of a wave?

1. The distance between two peaks
2. The maximum displacement of the wave from its rest position
3. The number of waves per second
4. The speed of the wave

17. Which type of electromagnetic radiation is most harmful to human DNA?

1. Gamma rays
2. Infrared
3. Radio waves
4. Visible light

18. What is the critical difference between sound and light in terms of transmission?

1. Light can only travel in straight lines
2. Light is faster than sound
3. Sound is a transverse wave; light is longitudinal
4. Sound requires a medium to travel; light can travel through a vacuum

19. What does the pitch of a sound depend on?

1. Amplitude
2. Frequency
3. The medium it travels through
4. Wavelength only

20. What is optical fibre used for, and which physical principle does it rely on?

1. Carrying electrical signals; using electrical resistance
2. Filtering light; using diffraction
3. Generating electricity; using the photoelectric effect
4. Transmitting light signals over long distances; using total internal reflection