3) Waves Flashcards
Define Wave motion:
Wave motion is the transfer of energy from one place to another, without transferring matter.
Define Wavefront:
Wavefront is the imaginary line joining all the crests on a wave.
Define Wavelength:
Wavelength is the distance between two consecutive crests, two consecutive troughs or between any two points in phase.
Define Frequency
Frequency is defined as the number of vibrations passing trough a point per unit time.
Define Transverse wave
A transverse wave ia a wave in which the direction of vibration is at right angles to the direction of propagation . Examples include: electromagnetic radiation, water waves and seismic S-waves (secondary) can be modelled as transverse.
Define Longitudinal wave:
For a longitudinal wave, the direction of vibration is parallel to the direction of propagation . Examples include: sound waves and seismic P-waves (primary) .
Define Refraction
It is the bending of light when light changes media. due to a change of speed
Define Reflection:
It is the bouncing back of waves after hitting a surface.
Define Diffraction:
Diffraction is the spreading of waves around obstacles.
Define Angle of incidence:
It is the angle between the incident ray and the normal.
Define Angle of refection:
It is the angle between the reflected ray and the normal.
Define Normal
A normal is a perpendicular line drawn to a surface , at the exact point where the incident ray hits the surface
Define Plane mirror:
A plane mirror is a mirror with a flat reflecting surface.
Define Critical angle:
Critical angle is that angle of incidence , for which the angle of refraction is 900.
Converging lens
A converging lens is a lens that allows all the parallel rays of light passing through it, to converge at a point.
Diverging lens:
A diverging lens is thinner in the middle than it is at the edges.
Thin lens:
A thin lens is a lens that has a negligible thickness in comparison to the radii of curvature of the lens surfaces.
Virtual image:
A virtual image is an image formed by rays of light that do not actually meet to form that image. A virtual image is formed when diverging rays are extrapolated backwards and does not form a visible projection on a screen
Real image:
A real image is an image formed by rays of light actually meeting at a point to form that image.
Dispersion of light:
The splitting of white light into its constituent colours when it is incident on a prism is called as dispersion of light.
Spectrum:
A band of colours formed as a result of dispersion is called as a spectrum.
Monochromatic light:
The visible light of a single frequency is described as monochromatic.
Electromagnetic spectrum:
An electromagnetic spectrum consists of a range of all types of electromagnetic radiations.
Compressions :
These are high pressure regions on a pressure wave( longitudinal wave)
Rarefactions:
These are low pressure regions on a pressure wave( longitudinal wave).
Crests
The highest point on a wave above the equilibrium
Troughs
The lowest point of a wavebelow equilibrium or rest
wave speed equation
frequency x wavelength
