Waves are a major topic in IGCSE Physics, covering both the general properties shared by all waves and the specific behaviours of light and sound. Understanding frequency and wavelength is central to this entire section of the syllabus.
1. Key Wave Properties
Every wave has an amplitude, wavelength, frequency and period. Amplitude is the maximum displacement from the rest position, wavelength is the distance between two identical points on consecutive waves, and frequency is the number of waves passing a point per second, measured in hertz.
2. Transverse vs Longitudinal Waves
In transverse waves, such as light and water waves, particles vibrate perpendicular to the direction of energy transfer. In longitudinal waves, such as sound, particles vibrate parallel to the direction of energy transfer, forming compressions and rarefactions.
3. The Wave Equation
The relationship between speed, frequency and wavelength is given by v = fλ, where v is wave speed, f is frequency, and λ is wavelength. This equation is one of the most frequently used formulas in the entire IGCSE Physics syllabus.
4. Applying the Wave Equation
IGCSE exam questions often give two of the three variables and ask students to calculate the third, so being comfortable rearranging v = fλ in different forms is an important exam skill.
Frequently Asked Questions
What is the unit of frequency?
Frequency is measured in hertz (Hz), where one hertz equals one wave cycle per second.
What is the main difference between transverse and longitudinal waves?
In transverse waves particles vibrate perpendicular to energy transfer, while in longitudinal waves particles vibrate parallel to the direction of energy transfer.
Conclusion
A solid understanding of basic wave properties makes the more specific topics of light, sound and the electromagnetic spectrum much easier to learn.