Refraction

Refraction always occurs whenever light travels from one medium to another.

• TRUE

• FALSE

The speed of light increases when it travels from glass to air.

• True

• False

Light bends towards the normal when it travels from glass to air.

• True

• False

The refractive index n of a medium is defined as

 $n\ =\ \frac{\sin\ i}{\sin\ r}$  

where i = angle of incidence in medium
            r = angle of refraction in vacuum or air

• True

• False

The diagram below shows the complete path of a ray of light travelling from air to a liquid. The refractive index of the liquid is given by

• $\frac{\sin\ 60\degree}{\sin\ 50\degree}$

• $\frac{\sin\ 30\degree}{\sin\ 50\degree}$

• $\frac{\sin\ 60\degree}{\sin\ 40\degree}$

• $\frac{\sin\ 40\degree}{\sin\ 50\degree}$

A ray of light in air is incident at an angle on one side of a rectangular glass block, as shown. Which ray diagram correctly describes the complete path of the ray of light?

(Determine if light bends towards or away from normal at each boundary)

• 
• 
• 
• 

A ray of light strikes the surface of a glass block at an angle of incidence of 45º. The refractive index of the glass is 1.8.

What is the angle of refraction inside the block?

• 23º

• 25º

• 45º

• 81º