A-Level Physics — Waves
1. Overview
The Waves topic focuses on how energy and information are transmitted through
oscillations without the transfer of matter. It introduces wave types, reflection, refraction,
diffraction, interference, and standing waves — fundamental ideas for understanding light,
sound, and electromagnetic waves.
2. Key Concepts
- Waves transfer energy and information, not matter.
- Transverse waves: vibrations perpendicular to the direction of energy transfer.
- Longitudinal waves: vibrations parallel to the direction of energy transfer.
- Examples: sound (longitudinal), light and EM waves (transverse).
3. Fundamental Wave Quantities
- Amplitude (A): Maximum displacement from equilibrium (m).
- Wavelength (λ): Distance between two equivalent points (m).
- Frequency (f): Number of oscillations per second (Hz).
- Time Period (T): Time for one cycle (s), where 𝑡 =
- Wave speed (v): 𝑣 = 𝑓 × 𝜆
4. Progressive Waves
- A progressive wave is an oscillation transferring energy through a medium or space.
- The particles oscillate around fixed positions without net movement.
5. Wavefronts and Rays
- A wavefront connects points at the same phase.
- A ray is a line showing the direction of wave travel (perpendicular to wavefronts).
6. Phase and Phase Difference
- Phase describes the position of a point in a cycle.
- Points one wavelength apart are in phase (phase difference = 2π rad or 360°).
- Formula: 𝛷 = (radians)
- Antiphase: points separated by (𝑛 + )𝜆 have opposite motion.
1. Overview
The Waves topic focuses on how energy and information are transmitted through
oscillations without the transfer of matter. It introduces wave types, reflection, refraction,
diffraction, interference, and standing waves — fundamental ideas for understanding light,
sound, and electromagnetic waves.
2. Key Concepts
- Waves transfer energy and information, not matter.
- Transverse waves: vibrations perpendicular to the direction of energy transfer.
- Longitudinal waves: vibrations parallel to the direction of energy transfer.
- Examples: sound (longitudinal), light and EM waves (transverse).
3. Fundamental Wave Quantities
- Amplitude (A): Maximum displacement from equilibrium (m).
- Wavelength (λ): Distance between two equivalent points (m).
- Frequency (f): Number of oscillations per second (Hz).
- Time Period (T): Time for one cycle (s), where 𝑡 =
- Wave speed (v): 𝑣 = 𝑓 × 𝜆
4. Progressive Waves
- A progressive wave is an oscillation transferring energy through a medium or space.
- The particles oscillate around fixed positions without net movement.
5. Wavefronts and Rays
- A wavefront connects points at the same phase.
- A ray is a line showing the direction of wave travel (perpendicular to wavefronts).
6. Phase and Phase Difference
- Phase describes the position of a point in a cycle.
- Points one wavelength apart are in phase (phase difference = 2π rad or 360°).
- Formula: 𝛷 = (radians)
- Antiphase: points separated by (𝑛 + )𝜆 have opposite motion.
