Chapter 13

Question 1

What is refraction?

Answer 1

Refraction is the bending of light as it passes from one medium to another

Question 2

What are the 2 laws of refraction?

Answer 2

1. The incident ray, the normal (at the point of incidence) and the refracted ray all lie on the same plane.
2. The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant for two given media

Question 3

What is the refractive index of a medium?

Answer 3

The refractive index of a medium is the the ratio of sine i to sine r when the light travels from a vacuum to that medium

Question 4

What is total internal reflection?

Answer 4

Total internal reflection occurs when the angle of incidence in the denser medium is greater than the critical angle → light is reflected back in the denser medium

Question 5

What is the critical angle?

Answer 5

The critical angle is the angle of incidence in the Denser medium corresponding to an angle of refraction of 90 degrees in the less dense medium (rarer medium)

Question 6

What is the power of a lens?

Answer 6

The power of a lens is the inverse of the focal length

Question 7

What are compound lenses?

Answer 7

Compound lenses are combinations of two or more lenses in contact with each other

Question 8

What is accommodation?

Answer 8

Accommodation is the process of adjusting the focal length of the lens to focus distant or near objects clearly on the retina

Question 9

What is short-sightedness?

Answer 9

Short-sightedness (myopia) means that distant objects cannot be seen clearly

Question 10

What is long-sightedness?

Answer 10

Long-sightedness (hyperopia) means that near objects cannot be seen clearly