Optics

Question 1

Refractive Index

Answer 1

The ratio of the sine of the angle of incidence to the sine of the angle of refraction when light passes from a vacuum into that medium

Question 2

Critical angle

Answer 2

When light travels from a denser to a rarer medium the angle of incidence whose angle of refraction is 90º is called the critical angle for those two mediums

Question 3

Snell’s Law

Answer 3

The ratio of the sine of the angles of incidence and transmission is equal to the ratio of the refractive index of the materials in the interface.
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant.

n1Sin1=n2Sin2 or sini/sinr

Question 4

Real Image

Answer 4

Formed by the actual intersection of light.

Question 5

Virtual Image

Answer 5

Formed by the apparent intersection of light rays. -1/v

Question 6

Law of reflection of light

Answer 6

The incident ray, the normal at the point of incidence and the reflected ray all lie in the same place.
On reflection from a smooth surface, the angle of reflected ray is equal to angle of incident ray.

Question 7

magnification

Answer 7

The ratio of the height of the image to the height of the object (m) m=v/u

Question 8

Total internal reflection

Answer 8

When the angle of incidence is greater than a certain limiting angle called the critical angle.