[LT] light

Question 1

how is visible light represented?

Answer 1

visible light is a form of energy and a part of the electromagnetic spectrum.

Question 2

what model is used to represent the path taken by light?

Answer 2

the ray model of light is used, which uses straight lines and arrows.

Question 3

what are the types of light rays?

Answer 3

there are three types: parallel rays, convergent rays, and divergent rays.

Question 4

define luminous objects.

Answer 4

luminous objects are objects that give off light on their own, such as the sun and lamps.

Question 5

define non-luminous objects.

Answer 5

non-luminous objects are objects that do not give off light on their own, like the moon and human beings.

Question 6

what is the reflection of light?

Answer 6

reflection is when light bounces off a surface.

Question 7

how do non-luminous objects become visible?

Answer 7

light from a source comes into contact with the surface of a non-luminous object > causing certain colors of light to be reflected.

Question 8

what are the six characteristics of images formed by plane mirrors?

Answer 8

• same size as the object
• upright
• have equal perpendicular
• distances from the mirror
• laterally inverted
• virtual

Question 9

what are the laws of reflection?

Answer 9

• the first law of reflection states that the angle of incidence is equal to the angle of reflection
• the second law of reflection state that the incident ray, reflected ray, and the normal at the point of incidence all lie in the same plane

Question 10

name three types of mirrors

Answer 10

plane mirrors, convex and concave mirrors

Question 11

property of a convex mirror

Answer 11

• curved outwards
• diminishes images
• provides a wider field of vision

Question 12

property of a concave mirror

Answer 12

• curved inwards
• magnifies images

Question 13

what are the two types of reflections?

Answer 13

regular reflection > on smooth surfaces
diffused reflection > on rough surfaces

Question 14

what are the seven steps for constructing ray diagrams?

Answer 14

1. locate the image behind the mirror.
2. draw the first reflected ray.
3. locate the point of incidence.
4. draw the first point of incidence.
5. draw the second reflected ray.
6. draw the second incident ray.
7. label

Question 15

what is the concept of reversibility of light?

Answer 15

light will follow the same path if its direction of travel is reversed

Question 16

when does refraction of light occur?

Answer 16

refraction of light occurs when
- a light ray passes from one medium to another of different optical density
- the angle of incidence is more than 0 degrees.

Question 17

how does light behave when it enters a medium of higher optical density?

Answer 17

light bends towards the normal when it enters a medium of higher optical density, slowing it down

Question 18

how does light behave when it enters a medium of lower optical density?

Answer 18

light bends away from the normal when it enters a medium of lower optical density, quickening it

Question 19

what is dispersion of light?

Answer 19

it occurs when white light passes through a different medium > causing each of the seven colors to slow down by different extents > and refract by different angles, resulting in the spreading out of colors.

Question 20

what is the electromagnetic spectrum

Answer 20

the electromagnetic spectrum includes various forms of electromagnetic radiation

Question 21

what are five applications of the electromagnetic spectrum?

Answer 21

• causing light pollution
• potential damage to eyes
• skin cancer due to overexposure
• producing x-ray images for medical diagnosis
• enabling daily activities.