Ch14 Light

Question 1

Law of reflection

Answer 1

angle of incidence = angle of reflection

Question 2

diffuse reflection

Answer 2

parallel light rays reflected from a rough surface are scattered in different directions

Question 3

Speculation reflection

Answer 3

parallel light rays are reflected of a smooth surface in a single direction

Question 4

Virtual image

Answer 4

Formed at a place where light rays appear to come from after having been reflected (is laterally inverted)

Question 5

Refraction

Answer 5

Change in the direction and speed of a plane wave when it travels across a boundary of two mediums with different densities at a non-zero angle

Question 6

What happens when light enters a more optically dense medium

Answer 6

It is refracted towards the normal

Question 7

What happens when light enters a less optically dense medium

Answer 7

It is refracted away from the normal

Question 8

What happens when light is refracted

Answer 8

The speed of the wave changes, causing a change in direction

Question 9

index of refraction

Answer 9

n = ci/cr

= incident wave speed/ refracted wave speed

Question 10

law of refraction(snell’s law)

Answer 10

n1 sinθi = n2 sinθr

Question 11

speed of light in air

Answer 11

1x10^8

Question 12

wave speed

Answer 12

v= frequency x wavelength

Question 13

Absorption of a wave

Answer 13

Heat the substance because it would gain energy from the waves
e.g Light is absorbed by darkness

Question 14

Transmission of a wave

Answer 14

Waves keep travelling in the same direction through an object
Light is transmitted by glass

Question 15

Diffraction of a wave

Answer 15

The spreading of waves around obstacles