What is the definition of critical angle?
The critical angle is the angle of incidence in the dense medium when the angle of refraction in the less dense medium is 90o
The critical angle is the angle of incidence in the less dense medium when the angle of refraction in the denser medium is 90o
The critical angle occurs when light is incident along the normal and passes straight through without being refracted
When does total internal reflection occur in glass?
When the angle of incidence in glass is less than the critical angle
When the angle of incidence in glass is greater than the critical angle
When the angle of incidence in glass is 0o
The critical angle for glass is approximately...
0o
42o
90o
Total internal reflection will not occur when...
Light travels from glass to air
Light travels from water to air
Light travels from air to water
Which of the following is an application of total internal reflection?
A temperature probe
A fibre optic cable
A spectacle lens used to correct short sight
Which of the following is the main advantage of keyhole surgery?
A patient doesn’t have to be cut open for a surgeon to see inside organs
It is cheap
It is non-toxic
What is an optical fibre?
A thin solid fibre of glass
A thin copper wire
Part of the optic nerve joining the back of the eye and the brain
The critical angle in glass is 42o. What happens if the angle of incidence at a glass-air boundary is 42o?
The light is refracted by 45o
The light is refracted by 90o
The light is totally internally reflected
The critical angle in glass is 42o. What happens if the angle of incidence at a glass-air boundary is 32o?
The light is refracted by less than 90o
The critical angle in glass is 42o. What happens if the angle of incidence at a glass-air boundary is 52o?