P14

Question 1

Lenses form images by

Answer 1

Refracting light and changing its direction

Question 2

What are the two main types of lenses?

Answer 2

Convex and concave

Question 3

When a ray of light hits a convex lens the ray buldges ___________. It causes rays of light parallel to the axis to be brought ______ together (converge) at the principle of focus.

Answer 3

Outwards, together, see picture on 82 for axis and principle of focus. And goodnotes 14.5/14.4 for how to draw them on ray diagrams

Question 4

A concave lens caves

Answer 4

Inwards. Causing parallel rays of light to spread out (diverge).

Question 5

What is the axis of a lens?

Answer 5

A axis is a line passing theough the middle of the lens

Question 6

What is the principle focus for a convex lens?

Answer 6

Is where rays hitting the lens parallel to the axis all meet

Question 7

What is the principle focus of a concave lens?

Answer 7

Is the point where rays hitting the lens parallel to the axis appear to all come from

Question 8

What is principle focus of the lens?

Answer 8

The point where the rays appear to focus

Question 9

What is the Focal length?

Answer 9

Refers to the refers to the distance between the centre of the lens and principal focus

Question 10

In terms of lenses, what is a real image and a virtual image?

Answer 10

Real Image
Where the light from an object comes together to form an image on a ‘screen’

Question 11

In terms of lenses, what is a virtual image?

Answer 11

Is when the rays are diverging, so the light from the object appears to be coming from a completely different place.
Look on cgp 83 and slides on showbie

Question 12

MAGNIFICATION =

Answer 12

IMAGE HEIGHT / OBJECT HEIGHT

IAM TRIANGLE

Question 13

How to produce ray diagram

Answer 13

Look in images in photos and in book 14.5

Question 14

When light focuses on the retina this is

Answer 14

Correct vision

Question 15

Light rays that focus infront of the retina is

Answer 15

Short-sighted vision

Question 16

Light rays that focus behind the retina is

Answer 16

Long sighted vision

Question 17

How do lenses correct short-sightedness?

Answer 17

It can be corrected by a concave lense, this cuases the rays to diverge before passing through the lens.
This assists in brining the rays to converge on the retina rather than in front of the retina

Question 18

How do lenses correct long-sightedness?

Answer 18

Corrected by a concave lens. This assists in bringing the rays to converge on the retina rather than behind it