Optics Pt.2

Question 1

What is the Mirror Equation?

Answer 1

1/f = 1/Do+1/Di

Question 2

What is Do and Di?

Answer 2

Do = distance of object
Di = Distance of image

Question 3

What does it mean in Di is positive? Negative?

Answer 3

Di is pos = Real image
Di is neg = Virtual image

Question 4

What does it mean if F is neg or pos?

Answer 4

F (-) = Concave mirror
F(+) = Convex Mirrpr

Question 5

What is the Magnification equation?

Answer 5

M = Hi/Ho = -Di/Do

Question 6

What is Hi and Ho

Answer 6

Hi = Height of image

Ho = Height of Object

Question 7

What does it mean if the height of the image is postitive?

Answer 7

If Hi/m is pos = Upright and virtual

If Hi/m is neg = Inverted/upside down and Real

Question 8

What is Do always?

Answer 8

Positive

Question 9

What does it mean if Di is positive? Negative?

Answer 9

Di pos = image is real
Di neg= image is virtual

Question 10

Ho is always ?

Answer 10

Positive

Question 11

What does it mean when image is upright? Inverted?

Answer 11

Hi is positive when upright
Hi is negative when inverted

Question 12

What does it mean if light can pass through F in a convex lens? What about when it can’t in a concave?

Answer 12

When light can pass through F in a convex lense F is positive

When light cannot pass through F in a concave lense F is negative

Question 13

In general what does + and - mean?

Answer 13

+ means real or upright
- means virtual or inverted

Question 14

What is diverging lense lost

Answer 14

L - between F & O
O- upright
S- smaller
T- virtual

Question 15

When object is beyond 2F in converging state lost

Answer 15

L - btw C and F
O- inverted
S- smaller
T- real

Question 16

When object is at 2F in converging what is lost

Answer 16

L- at 2F
O- inverted
S- same size
T-real

Question 17

Between 2F and F what is LOST converging

Answer 17

L- beyond 2F
O- inverted
S- bigger
T- real

Question 18

At F lost converging

Answer 18

No image forms

Question 19

Between F and O state lost converging

Answer 19

L- beyond 2F
O- upright
S- bigger
T- virtual

Question 20

Describe a converging lense

Answer 20

Lense that are thickest in middle and cause incident parallel to converge thro single point after refraction

Question 21

Describe diverging lenses

Answer 21

Thinnnest in middle and cause incident parallel light rays to spread apart after refraction

Question 22

What are lenses made of

Answer 22

Glass and plastic

Question 23

What is refraction

Answer 23

The bending /change of direction of light when travelling from one medium to another one

Question 24

What happens when light passes into a medium that is more dense? Less?

Answer 24

When light passes through a medium that is more dense, it will slow down, when it passes through something less dense, it will speed up

Dense is like thicker, so water is more dense than air. Makes sense cuz passing through water will slow u down rather than air

Question 25

What is the speed of light in a vacuum, water and acrylic?

Answer 25

Vacuum: 3.00 x 10^8 m/s Water: 2.26 x10^8 m/s Acrylic : 1.76 x 10^8 m/s

Question 26

When does light bend away from Normal, give an example what about towards?

Answer 26

Light bends AWAY from normal when light goes into a less dense material, speed of light is greater. eg air Light bends TOWARDS the normal when speed of light is less in a medium, or when a medium is more dense. Eg, water

Question 27

What does fast stand for

Answer 27

F- faster A-away S-slower T-towards Used to describe air to water ray, Lea dense to more dense therefore bending away

Question 28

As incident angle increases what happends to refraction angle

Answer 28

Increases ( angle is ray to normal)

Question 29

What is refractive index

Answer 29

“N” It is the measure of optical density, the higher the value the more optically dense it is eg zircon (1.92) is more optically dense than glycerin (1.47)

Question 30

What is a critical angle?

Answer 30

When light refracts at 90 degrees

Question 31

What’s a total internal reflection

Answer 31

When the incidence angle exceeds the critical angle total internal reflection happends

Question 32

What are the conditions for total internal reflection

Answer 32

1. Second medium has to be less dense and lower index of refractions. ,love from more dense to less dense 2. Incident angle exceeds CA

Question 33

What is lucite wrapped in and why does any life enter reflect?

Answer 33

Lucite is wrapped in cladding of lower index of refraction Lucite has a very small CA,any light that enters will reflect allowing waves to travel very far

Question 34

What is the CA first glass? Diamond?

Answer 34

Glass: 41.4, angle of incidence is always 45. Results in clear image formed Diamond: 25 ca, sparkle comes from tir

Question 35

What are the 3 seniors and describe them for TIR

Answer 35

1. The normal one where it moves towards or away 2. When the CA and TIR are equal, it refracts at 90 degrees 3.TIR, when the second medium has less density, and incident angle is bigger then CA

Question 36

Cornea

Answer 36

Transparent front part of eye that covers iris and pupil. Together with lens and the cornea will refract light

Question 37

Pupil

Answer 37

Hole that allows light into the eye

Question 38

Iris

Answer 38

The eye colour, circular band of muscle that controls amount of light entering

Question 39

What happens in dim and bright light

Answer 39

Dim - pupil dilates Bright-pupil constricts

Question 40

Retina

Answer 40

The inner lining at the back of the eye, contains photoreceptors which are sensitive to light images formed are inverted

Question 41

Blind spot

Answer 41

Has no photoreceptors, cannot detect light. Optic nerve connects eye to brain

Question 42

what do muscles do to focus on distant objects? Close objects?

Answer 42

Relax which makes lens flatter and thinner for distant objects Muscles contract making lense thicker and rounder, to focus on close objects

Question 43

Myopia

Answer 43

Nearsighted Eye is too long or cornea is too curbed, image appears before Retina Hiw to fix? Diverging lenses spread out rays just right amount before they enter the eye so the image will converge properly onto retina

Question 44

Hyperopia

Answer 44

Far sightedness Eye is too short or lems is flatter, image appears behind retina How to fix Converging lenses converge rays just the right amount before entering eye to image will converge properly onto retina

Question 45

Presbyopia

Answer 45

Stuff lenses become a problem with age making it difficult for cillary muscles,especially to change shape of lense Can’t focus on nearby objects Nearsighted person develops presbyopia, bifocals are required

Question 46

Astigmatism

Answer 46

Irreg shaped cornea Football shapes rather than baseball Results in blurry vision