What is the law of reflection?
The angle of incidence equals the angle of reflection
The angle of incidence is less than the angle of reflection
The angle of incidence is more than the angle of reflection

How do we describe the image in a plane mirror?
Virtual and upright
Virtual and upside down
Virtual only

When does total internal reflection occur?
When the angle of incidence equals the critical angle
When the angle of incidence is less than the critical angle
When the angle of incidence is beyond the critical angle

How do we calculate the critical angle?
sin c = 1 ÷ n
sin c = 1 × n
sin n = 1 × c

Where do we use total internal reflection?
For wireless signals
Inside optical fibres
Inside analogue cables

Which of these is untrue about ray diagrams?
The arrowheads show the direction of the light
Lines must always be straight
More arrowheads on lines means a brighter light

What is the term that describes the changing direction of light when it changes medium?
Reflection
Dispersion
Refraction

Which statement explains why refraction occurs?
Light rays curve
Light rays change speed
Light rays change direction

Which of these is an advantage of using optical fibres?
Fibres are rigid and do not bend
Light is lost as it travels along the fibre
Light travels very quickly

Where are optical fibres often used?
By doctors in hospitals
By teachers in schools
By lawyers in court