the increase or decrease in size of an image produced by an optical system compared to the true size
Magnification
a converging lens
Convex lens
a lens that possesses at least one surface that curves inwards It is a diverging lens, meaning that it spreads out light rays that have been refracted through it
Concave lens
a line that is perpendicular to the light's wavefronts; its tangent is collinear with the wave vector
Light rays
the angle of incidence beyond which rays of light passing through a denser medium to the surface of a less dense medium are no longer refracted but totally reflecte
Critical angle
the degree to which a refractive medium retards transmitted rays of ligh
Optical density
a wave vibrating in the direction of propagation
Longitudinal wave
a wave vibrating at right angles to the direction of its propagation
Transverse wave
A substance that makes possible the transfer of energy from one location to another, especially through waves
Medium
the number of crests of a wave that move past a given point in a given unit of time
Frequency
the time needed for one complete cycle of vibration to pass a given point
Period
a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a medium such as air or water
Sound
the process by which a beam of light or other system of waves is spread out as a result of passing through a narrow aperture or across an edge
Diffraction
combination of two or more electromagnetic waveforms to form a resultant wave in which the displacement is either reinforced or canceled
Interference
the point at which rays or waves meet after reflection or refraction, or the point from which diverging rays or waves appear to proceed
Focal point
change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated

Refraction
the angle made by a reflected ray with a perpendicular to the reflecting surface
Angle of refraction
the angle that an incident line or ray makes with a perpendicular to the surface at the point of incidence
Angle of incidence
a surface that is either plane, concave, or convex and that reflects rays of light.
mirror
a disturbance on the surface of a liquid body
wave