Waves and Vibrations Flashcards
What are electromagnetic waves?
These are waves that progress through space without the need for a substance. The vibrating electric field generates a vibrating magnetic field, which generates a vibrating electric further away and so on.
What are the electromagnetic waves?
Radio waves Microwaves Infrared radiation Visible light Ultraviolet radiation X rays Gamma radiation
What are longitudinal waves?
Waves in which the direction of vibration of the particles is parallel to the direction in which the wave travels. E.g sound waves.
What are transverse waves?
Waves in which the direction of vibration is perpendicular to the direction in which the wave travels. E.g Electromagnetic waves.
When are transverse waves plane polarised and unpolarised?
They are plane polarised if the vibrations stay in one plane only. If the vibrations change from one plane to another, the waves are unpolarised.
What are polarised light waves?
Polarised light waves are light waves in which the vibrations occur in a single plane. The process of transforming unpolarised light into polarised light is known as polarisation.
Define displacement.
The displacement of a vibrating particle is its distance and direction from its equilibrium position.
Define amplitude.
The amplitude of wave is the maximum displacement of a vibrating particle. For a transverse wave, this is the height of wave crest or the depth of a wave trough from the middle.
Define wavelength
The distance between successive crests of a wave.
What is the period of a wave?
The time for one complete wave to pass a fixed point.
Define frequency
The number of complete waves passing a point per second. Unit = Hz.
The higher the frequency of a wave…
…the shorter its wavelength.
