Waves, light and sound Physics - IGCSE

Wave length, frequency, wave speed, electromagnetic spectrum, lens, sound waves and more....
Transverse wave
In this type of wave, vibrations of the particles are right angled to the direction of wave motion. Examples are light waves, water waves and other electromagnetic waves.
Longitudinal wave
In this type of wave, vibrations of the particles are parallel to the direction of their wave motion. Examples are sound waves etc.
It is the distance between two successive peaks or crests in a wave.
It is the number of oscillations or cycles per second and is measured in Hertz.
It is the maximum displacement of the wave from the central position of the wave (height of the wave).
Time period
It the time taken for one complete oscillation of the wave motion.
It is a process in which when a wave enters a new medium, at an angle then the wave front changes its direction.
It is a process in which wave fronts change shape when they pass the edge of an obstacle or go through a gap.
It is the direction or path in which light is travelling.
It is the process where a light ray changes direction when it bounces off a barrier in the medium.
Law of reflection
This law states that the angle of incidence is equal to the angle of reflection.
Virtual image
This is the image formed in a plane mirror and it forms in locations where light doesn't actually pass. The image cannot be taken onto a screen.
Real image
This is the image formed in places where light passes and so it can be taken onto a screen.
Critical angle
It is the angle of incidence at which all refraction stops, and it is measured from an optically dense medium to less dense medium.
Dispersion of light
It is when white light is passed through a triangular prism, it is split into a spectrum of different colours.
Electromagnetic spectrum
It is the spectrum of electromagnetic radiations. They all travel at the speed in a vacuum.
Gamma rays
They are rays produced by radioactive nuclei and transfer more energy than X-rays. They can be used to kill cancer cells.
They are rays produced when high energy electrons are fired at a metal target. It can be used to detect bone fractures.
Ultra violet rays
They a re rays produced from the sun that gives you a sun tan. It can cause skin cancer and damage eye sight.
Infrared radiation
All heated objects emit this type of radiation in the form of electromagnetic waves. It is used in cooking and in TV remote controls.
Micro-wave radiation
They are radiation in the form of high frequency radio waves. Used in radar positioning and for cooking.
Radio waves
They are electromagnetic waves with the longest wavelengths and lowest frequency. It is used to transmit television and radio programmes.
Ultra sound
This is a sound that has a frequency above 20000 Hertz and is used for navigation purposes.
Infra sound
This is a sound that has a frequency below 20 Hertz.
It is the sound heard after the reflection of a sound wave from other hard surfaces.