Waves Definitions Flashcards
1
Q
normal
A
the line drawn at right angles to a surface at the point where a ray hits the surface
2
Q
angle of incidence
A
the angle between the incident ray and the normal drawn at the point where the ray hits the surface
3
Q
angle of reflection
A
the angle between the reflected ray and the normal drawn at the point where the ray hits the surface
4
Q
refractive index
A
the ratio of the speeds of a wave in two different regions
5
Q
focal length
A
the distance from the centre of the lens to its principal focus
6
Q
principal axis
A
the line passing through the centre of a lens perpendicular to its surface
7
Q
principal focus (focal point)
A
the point at which rays of light parallel to the axis converge after passing through the converging lens
8
Q
ultrasound
A
sound with a frequency higher than 20 kHz
