Key Concepts: Waves transfer energy without transferring matter. Key properties include wavelength ($\lambda$), frequency ($f$), and amplitude ($A$). Wave equation: $v = f\lambda$. The electromagnetic spectrum includes radio, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Sound waves are mechanical waves requiring a medium.
Section A: Wave Properties
1. State the SI units for angle, frequency, wavelength, wave speed and time. [5]
2. Define amplitude, wavelength, frequency, period and wavefront. [5]
3. A wave has frequency 50 Hz and wavelength 4 m. Calculate wave speed and period. [3]
4. Explain the difference between transverse and longitudinal waves and give one example of each. [3]
5. Explain how waves transfer energy and information without transferring matter. [2]
6. Calculate wavelength for: (a) a radio wave of frequency 100 MHz in free space (speed $3.0 \times 10^8\,m/s$), (b) a sound wave of frequency 170 Hz in air (speed $340\,m/s$). [4]
7. State two things all waves can do when they meet a boundary. [2]
8. Explain the Doppler effect and give one example. [3]
Section B: Electromagnetic Spectrum
9. List the electromagnetic spectrum in order of increasing frequency and decreasing wavelength, and state that all EM waves travel at the same speed in free space. [3]
10. List the visible colors in order from red to violet. [2]
11. Give one use for each: radio, microwave, infrared, visible, ultraviolet, X-ray, gamma. [7]
12. State one harmful effect of excessive exposure to microwaves, infrared, ultraviolet and gamma rays. [4]
Total marks: 43
Mark Scheme
1. degree, Hz, m, m/s, s [5]
2. Correct definitions (1 each) [5]
3. $v = f\lambda = 50 \times 4 = 200\,m/s$ [1]; $T = 1/f = 0.02\,s$ [2]
4. Transverse vs longitudinal and examples [3]
5. Energy transfer without matter transfer [2]
6. (a) $\lambda = 3.0 \times 10^8 / 1.0 \times 10^8 = 3.0\,m$ (b) $\lambda = 340/170 = 2\,m$ [4]
7. Reflection and refraction [2]
8. Observed frequency changes due to motion (siren/galaxy redshift) [3]
9. Radio -> microwave -> infrared -> visible -> ultraviolet -> X-ray -> gamma; same speed in free space [3]
10. Red, orange, yellow, green, blue, indigo, violet [2]
11. Any correct use for each region [7]
12. Microwaves: internal heating; IR: skin burns; UV: eye/skin damage; gamma: mutations/cancer [4]