Lenses

Question 1

How fast is the speed of light?

Answer 1

3.00 x10^8 m/s

Question 2

What is the formula for finding the index of refraction with speed?

Answer 2

Index= speed of light/speed in substance

Question 3

What is the variable used for the speed of light?

Answer 3

c

Question 4

What is the variable for speed in a given substance?

Answer 4

v

Question 5

What is the rule for index and their speed?

Answer 5

Lower the index, higher the speed

Question 6

Can anything be faster than light?

Answer 6

No

Question 7

What are more then one index called?

Answer 7

Indices

Question 8

What is refraction of light?

Answer 8

When a Ray passes between media with different speed causes the Ray to change direction

Question 9

When you go from a low index to a high index which way does the Ray bend?

Answer 9

Towards the normal

Question 10

When a light rays goes from a high index to a low index which way does it bend?

Answer 10

Away from the normal

Question 11

What is Snells law formula?

Answer 11

N1(SinØ1) = N2(SinØ2)
First index (sin of incident angle)
= Second index ( sin of refracting angle)

Question 12

What is total internal reflection? (TIR)

Answer 12

When a ray travels from high index to low index (bends away from normal) and the angle of refraction eventually equals 90 degrees, any angle of incidence greater then the critical angle causes the entire Ray to reflect off the boundary

Question 13

What is the critical angle?

Answer 13

The angle of incidence when the angle of refraction is 90 degrees

Question 14

What is the formula used to find the critical angle?

Answer 14

SinØcritical = N2/N1

Question 15

What index does the Ray have to go from for TIR to take place?

Answer 15

Must go from high index to low index so it bends away from normal

Question 16

What is index for air?

Answer 16

1.0003

Question 17

What is index for water?

Answer 17

1.33

Question 18

How do convex (CONVERGING) lenses work?

Answer 18

They refract rays inwards towards a real focal point

Question 19

What’s the difference between Ray diagrams with Mirrors and lenses?

Answer 19

The first two rules are the same. The third rule for lenses says that rays the ought the optical centre reflect straight back the same way, not through C

Question 20

What’s the difference for images between mirrors and lenses?

Answer 20

Lenses images are virtual on the same side as the object and are real on the opposite side of the mirror.

Question 21

Where is the image located for an object located beyond 2F on a convex lense?

Answer 21

Between f and 2f on opposite side of mirror
Inverted
Smaller
Real

Question 22

Where is the image located for an object located Inbetween f and the lense on a convex mirror?

Answer 22

The image is Inbetween f and lense on same side
Erect
Larger
Virtual

Question 23

Where is the image located for an object inbetween 2f and f on a convex lense?

Answer 23

Located beyond 2f on opposite side
Inverted
Larger
Real

Question 24

What is the difference in shape between concave and convex mirrors?

Answer 24

Convex starts thin then gets thick in the middle

Concave starts thick then gets skinny in the middle

Question 25

What factor, other then curve of lense, affects the location of the focal point?

Answer 25

``` The type of glass. Higher index class means closer focal point Lower index glass means further focal point ```

Question 26

What is chromatic aberration? And what causes it?

Answer 26

It is when different colours of light bend at slightly different angles when passing through a lens. It is caused by the lights having slightly different speeds causing them to bend at different angles

Question 27

Why is chromatic aberration a problem? And to who?

Answer 27

It causes images to have slight coloured fringes. To people trying to shoot high precision images

Question 28

What are the two ways to fix chromatic aberration?

Answer 28

Use an achromatic lens (concave and convex lense fused together) Special low dispersion glass fixes it as well

Question 29

What is the difference between concave and convex lenses in terms of f

Answer 29

Concave lenses have a negative f value always | Convex lense have a positive f value always

Question 30

What occurs when the change in speed between two media increases?

Answer 30

The Ray will be bent bigger and will reach 90 degrees sooner

Question 31

How does the size of the critical angle change as the index of refraction increases?

Answer 31

The critical angle gets smaller as the refractive index increased