SP5

Question 1

What is the law of reflection?

Answer 1

Angle of incidence = Angle of reflection
Incident ray, reflected ray, and normal all lie in the same plane

Question 2

What colours make white light?

Answer 2

ROYGBIV (Red, Orange, Yellow, Green, Blue, Indigo, Violet)

Question 3

What colour does a green object appear under red light?

Answer 3

Black (it absorbs red light)

Question 4

Convex (converging) lens characteristics:

Answer 4

bring parallel rays of light together at focal point
Forms real or virtual images
fixes long-sightedness

Question 5

Concave (diverging) lens characteristics:

Answer 5

spread out parallel rays of light DDD
Always forms virtual images
Used in correcting short-sightedness

Question 6

List the EM waves in order of decreasing frequency:

Answer 6

Gamma rays
X-rays
Ultraviolet
Visible light
Infrared
Microwaves
Radio waves

Question 7

Which EM wave has the longest wavelength?

Answer 7

Radio waves

Question 8

Microwave uses:

Answer 8

Cooking (2.45GHz absorbed by water)
Satellite communications

Question 9

X-ray uses:

Answer 9

Medical imaging
Airport security

Question 10

Why is UV dangerous?

Answer 10

Can cause skin cancer and eye damage

Question 11

How do ozone layers protect us?

Answer 11

Absorbs harmful UV radiation

Question 12

What is diffuse reflection?

Answer 12

reflection from rough surface, the light rays scatter in all directions

Question 13

What is specular reflection?

Answer 13

reflection from smooth surface like a mirror, the light rays bounce off in an orderly way