Chapter 13 - Light

Normal

Line perpendicular to the reflecting surface

Angle of incidence

Angle between the incident ray and the normal

Angle of reflection

Angle between the reflected ray and the normal

characteristics of an image formed in a plane mirror

Same size as object

Virtual

Laterally Inverted

Same distance from the mirror

Upright

refraction

The bending of light as it travels from one medium to another due to change in speed of light

when a light ray goes from a rarer to denser medium

speed of light decreases

Ray bends towards normal

when a light ray goes from a denser to rarer medium

Speed of light increases

Ray bends away from normal

refractive index formulas

n = c/v

n = sin I/ sin r

n = sin r/ sin I

n = 1/sin c

Critical angle

Angle of incidence for which the angle of refraction is 90.

Total internal reflection

When the angle of incidence is greater than the critical angle, the ray is reflected back in the same medium

use of optic fibers in communication

Used to transfer information using light or infrared rays. The rays reflect inside the fibre because the angle of incidence is greater than the critical angle

Use of optic fibers in medicine

Used to see inside a patient before or during surgery. Light travels along thr Fibre, reflects back through the fiber to detecting equipment outside.