Refraction

Question 1

Refraction

Answer 1

The bending of a ray of light when it goes from one medium to another is called refraction

Question 2

Refraction directions:

Answer 2

When light travels from a rarer to a denser medium it is refracted towards the normal
When light travels from a denser to a rarer medium it is refracted away from the normal

Question 3

The laws of refraction of light:

Answer 3

Law 1: The incident ray, the normal at the point of incidence and the refracted ray all lie on the same plane
Law 2: The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant

Question 4

Refractive index of a medium

Answer 4

The refractive index of a medium is the ratio of the sine of the angle of incidence to the sine of the angle of refraction when light travels from a vacuum into that medium

Question 5

The refractive index between two media

Answer 5

The refractive index between two media is the ratio of the sine of the angle of incidence to the sine of the angle of refraction when light travels from one of those media into the other

Question 6

Critical angle

Answer 6

When light travels from a denser to a rarer medium, the angle of incidence whose corresponding angle of refraction is 90 degrees is called the critical angle (C) for those two media

Question 7

Total internal reflection

Answer 7

When light going from a denser to a rarer medium strikes the second medium with an angle of incidence greater than the critical angle, it does not enter the second medium. it is all reflected back in the denser medium. This is called total internal reflection

Question 8

Optical fibre

Answer 8

A very thin transparent rod (usually of glass) through which light can travel by total internal reflection is called an optical fibre