Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Final Review > Lenses > Flashcards

Lenses Flashcards

1
Q

Lens Definition

A

A transparent object with at least one curved side that causes light to refract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the terms that are used to describe lenses, as well as mirrors?

A

Plane, Concave, and Convex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How are lenses different from mirrors?

A

They have two sides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

True or False: Either side of a lens can be plane, concave, or convex.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the word used to describe when parallel light rays travel through a lens and spread away from a common point?

A

They diverge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the word used to describe when parallel light rays travel through a lens and come together to a common point?

A

They converge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do converging lenses have?

A

One or two convex surfaces and are thicker in the centre than on the edges.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What do diverging lenses have?

A

One or two concave surfaces and are thinner in the centre than on the edges.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

True or False: There is one combination of surfaces that causes light rays to neither converge nor diverge.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens when light rays enter a piece of glass with a plane surface?

A

The rays bend toward the normal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens when light rays are on the far side of the glass?

A

The rays will bend away from the normal by the same amount that they first bent toward the normal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

All rays shift to the side (are laterally displaced) but when they leave the glass, what directions are they travelling in?

A

The same direction as they entered.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

True or False: Because there has been no change in the direction of the rays relative to each other, a piece of glass cannot be considered a lens.

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Converging Lense Definition

A

A lens that brings parallel light rays toward a common point.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the shape that most easily illustrates how parallel rays are brought together?

A

A lens that is convex on both sides.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens when rays are incident on the surface on the left side of the lens? Thus, what happens next?

A

They move from a fast medium to a slow medium. The rays refract toward the normals causing the rays to converge slightly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens when the light rays leave the second surface of the lens? Thus, what happens next?

A

They move from a slow medium to a fast medium, and refract away from the normals. Because of the direction of the normals at this surface, the rays continue to converge.

18
Q

Diverging Lens Definition

A

A lens that spreads parallel light rays away from a common point.

19
Q

What is a good example of a diverging lens?

A

A lens that is concave on both sides.

20
Q

True or False: The principal axis of a lens is a straight line that passes through the centre of the lens, normal to both surfaces of the lens, as with mirrors.

A

True

21
Q

What happens when rays that are parallel to the principal axis pass through a converging lens?

A

The rays intersect at a point.

22
Q

As with a concave mirror, what is this point called?

A

The Focal Point

23
Q

What happens after parallel rays pass through a diverging lens?

A

The rays diverge.

24
Q

Why are there two focal points for a lens?

A

Because light can pass through a lens from either side.

25
Q

True or False: These two focal points are the same distance from the centre of the lens.

A

True

26
Q

What is the distance from the centre of the lens to the focal point called?

A

The focal length.

27
Q

What does the position of the focal point for a lens depend on?

A

Both the index of refraction of the lens material and curvature.

28
Q

What do lenses with the same shape but higher indices of refraction do more of? How does this affect the focal point?

A

Bend rays more, making the focal point closer to the lens.

29
Q

True or False: Lenses with larger curvatures but with the same index of refraction have the same effect.

A

True

30
Q

Chromatic Aberration Definition

A

The dispersion of light through a lens.

31
Q

How to draw Ray Diagram for Converging Lens (3 points)

A

-Ray entering parallel to principal axis goes through focal point on the other side.
-Ray travelling through centre of lens keeps travelling in the same direction.
-Ray that enters from the focal point leaves the lens parallel to the principal axis.

32
Q

Characteristics of Image of Object between the Focal Point and Converging Lens

A

-Farther from lens than object.
-Upright
-Larger than object
-Virtual

33
Q

Characteristics of Image of Object between one and two focal lengths from the converging lens

A

-Farther from lens than object
-Inverted
-Larger than object
-Real

34
Q

Characteristics of Image of Object beyond two focal lengths from the converging lens

A

-Closer to lens than object.
-Inverted
-Smaller than object.
-Real

35
Q

How to draw ray diagram for Diverging Lens (4 points)

A

-Ray entering parallel to principal axis appears as if it is coming from the focal point on the object side.
-Ray travelling through the centre of the lens keeps travelling in the same direction.
-Ray that is directed toward the focal point on the opposite side of the lens leaves the lens parallel to the principal axis.
-Because the rays diverge after leaving the lens, the rays do not meet and rays need to be extended backward until they meet in order to find out where they are located.

36
Q

Characteristics of Image formed by Diverging Lens

A

-Closer to lens than object
-Upright
-Smaller than object
-Virtual

37
Q

In the thin lens equation, the distance from object to optical centre is what?

A

Always positive

38
Q

Sign of distance from image to optical centre for both types of images

A

-Positive for Real Images; image on opposite side of the lens.
-Negative for Virtual Images; image on the same side of the lens as object.

39
Q

Sign of distance from
optical centre to
principal Focus for both types of lenses

A

-Positive for Converging Lenses
-Negative for Diverging Lenses

40
Q

Sign of height of images (by orientation)

A

-Positive if upright
-Negative if inverted

Final Review (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions