P2.2 Lights

Question 1

What does the law of reflection state?

Answer 1

Angle of incidence is always equal to the angle of reflection

Question 2

In a ray diagram, how is a normal represented?

Answer 2

Dashed lines

Question 3

What angle describes the angle between the normal and the incident ray?

Answer 3

Angle of incident

Question 4

What angle describes the angle between the normal and the reflected ray?

Answer 4

Angle of reflection

Question 5

What are the properties of an image in a plane mirror? (4)

Answer 5

Virtual Image
Same size as the object
Laterally inverted
Same distance behind the mirror as the object is in front of the mirror

Question 6

What is meant by the term “refraction” and what causes it?

Answer 6

It is the change of direction of a beam of light as it travels from one material to another.

Caused by the change in speed in different materials.

Question 7

What angle describes the angle between the normal and the refracted ray?

Answer 7

Angle of refraction

Question 8

What is the speed of light as it travels through air (or a vacuum)?

Answer 8

300 million m/s

Question 9

What is the speed of light as it travels through water?

Answer 9

225 million m/s

Question 10

What is the speed of light as it travels through glass?

Answer 10

200 million m/s

Question 11

When light speeds up, will it bend away or towards the normal?

Answer 11

Bends AWAY from normal

Question 12

When light slows down will it bend away or towards the normal?

Answer 12

Bends TOWARDS the normal

Question 13

What colour refracts ,when passed through a glass prism, the least and why?

Answer 13

Red
Travels fastest in glass

Question 14

What colour refracts ,when passed through a glass prism, the most and why?

Answer 14

Violet
Travels slowest in glass

Question 15

What is meant by dispersion?

Answer 15

The splitting of white light into its component colours

Question 16

What are lenses?

Answer 16

A specially shaped piece of glass or plastic

Question 17

What are the 2 types of lenses?

Answer 17

Converging
Diverging

Question 18

What is another name gave to a converging lens?

Answer 18

Convex

Question 19

What is another name gave to a diverging lens?

Answer 19

Concave

Question 20

What type of lens is one at which the lens is thickest at its centre and least thick at its edges?

Answer 20

Converging

Question 21

What type of lens is one in which the lens is thickest at its edges and least thick at its centre?

Answer 21

Diverging

Question 22

What is the defining feature of a converging lens?

Answer 22

Rays of light parallel to the principal axis of a converging lens all converge at the principal focus on the opposite side of the lens

Question 23

What is the focal length?

Answer 23

The distance between the principal focus and the optical centre

Question 24

What is the principal focus?

Answer 24

A point on the principal axis of a convex lens through which rays of light parallel to the principal axis pass after refraction in the lens

Question 25

What is the principal axis?

Answer 25

A straight line joining the principal foci and passing through the optical centre of a convex lens

Question 26

List the 4 things an image in a concave lens will always be.

Answer 26

Erect Virtual Smaller than the object Placed between the object and the lens

Question 27

In an object where the position is between lens and F, where would the location of the image be?

Answer 27

On same side of lens as object but further away from the lens

Question 28

In an object where the position is between lens and F, list the 3 properties.

Answer 28

Virtual Erect Larger

Question 28

In an object where the position is between lens and F, list the application.

Answer 28

Magnifying glass

Question 29

In an object at F, where would the image be?

Answer 29

Infinity

Question 30

In an object at F, list its 3 properties of the image

Answer 30

Real Inverted Larger

Question 31

What is the application of an object at F?

Answer 31

Searchlight

Question 32

At an object between F and 2F, where would the image be?

Answer 32

Beyond 2F

Question 33

At an object between F and 2F, list the 3 properties of the image.

Answer 33

Real Inverted Larger

Question 34

At an object between F and 2F, what is its application?

Answer 34

Cinema Projector

Question 35

At an object at 2F, what is the location of the image?

Answer 35

At 2F

Question 36

At an object at 2F, list thee 3 properties of the image.

Answer 36

Real Inverted Same size

Question 37

At an object at 2F, what would be its application?

Answer 37

Telescope-erecting lens

Question 38

At an object just beyond 2F, where would the image be?

Answer 38

Between F and 2F

Question 39

At an object just beyond 2F, list the 3 properties.

Answer 39

Real Inverted Smaller

Question 40

At an object just beyond 2F, what is the application?

Answer 40

Camera

Question 41

At an object which is very far from the lens, where would the image be?

Answer 41

At F

Question 42

At an object which is very far from the lens, list the 3 properties.

Answer 42

Real Inverted Smaller

Question 43

At an object which is very far from the lens, what is the application?

Answer 43

Camera