turning Point Questions

Question 1

Diffraction is a change in direction of propagation due to

Answer 1

Edge phenomenon

Question 2

Fresnel, secondary wavelets undergo mutual interference, true or false

Answer 2

True

Question 3

Constructive interference in a single slit diffraction

Answer 3

asin(theta)=m (lambda)

A=slit width

Question 4

What is the type of diffraction, if the source of light and the screen are at finite distance from the diffraction aperture?

Answer 4

Fresnel

Question 5

In the single slit diffraction, when the aperture size ‘a’ decreases, what happens to the diffraction pattern?

Answer 5

Spreads out

Question 6

What os the type of diffraction, if the source of light and the screen are at a finite distance from the diffraction aperture

Answer 6

Fresnel diffraction

Question 7

The smallest letters that a person with 20/2 snellen acuity can resolve have detail that subtends at angle of ____

Answer 7

1’

Question 8

What happens to diffraction image point in a phase plate when the alternate zones are phase shifted by 180 degrees?

Answer 8

Brighter

Question 9

When a diffractive structure (phase plate) is embedded on one side of the refractive lens, the lens is called

Answer 9

Hybrid

Question 10

In the diffractive multifocal lens, when m=0 the power of the lens is

Answer 10

Zero

Question 11

In a diffractive multifocal lens, the first order diffraction generates the _____ power

Answer 11

Add power

Question 12

Wearing multifocal lens causes some patients see shadows formed onto their retina. This condition is called _____

Answer 12

Negative dysphotopsia

Question 13

The strength of the iridescence in a mollusk shell is due to _____ and _______

Answer 13

Groove density and surface quality

Question 14

Fresnel’ lans increases the luminosity of the lighthouse lamp by a factor of _____

Answer 14

4

Question 15

The energy allocation, in diffractive multifocal lens, between 0th order and 1st order is known as _____

Answer 15

Diffraction efficiency

Question 16

What causes the interference pattern to form 3d holography image

Answer 16

Phase difference

Question 17

While using a coherent source to view a recorded holography image, which of the diffraction orders does one view the image?

Answer 17

-1 order

Question 18

In a typical human eye when the pupil size increases, which one of the following will increasingly affect vision

Answer 18

Aberration

Question 19

Diffraction is a change in direction due to

Answer 19

Edge phenomenon

Question 20

What equation is for constructive interference in a single slit diffraction

Answer 20

Asin(theta)=m(lambda)

Question 21

Which of the scattering will happen when the particles are smaller than the wavelength of the light

Answer 21

Rayleigh

Question 22

What is the scattering profile of Mie scattering

Answer 22

Mostly forward

Question 23

Bluer the light, more the light scatter

Answer 23

True

Question 24

For a healthy non-cataractous eye, the intraocular scatter increases by 2x at the age of ____ compared to young eyes

Answer 24

65

Question 25

In the blue/blue-green eyes, intraocular scatter is caused by pigmentations in the scleral wall, iris and ________

Answer 25

Fundus

Question 26

Which of the following refractive surgery techniques causes an increase of intraocular scatter by a factor of 4?

Answer 26

RK

Question 27

Corneal transmittance is dependent on

Answer 27

Wavelength

Question 28

When wave 1 and wave 2 are in phase, but wave 1 travels an extra distance ( or path difference) equal to 1 wavelength, then this interference is called

Answer 28

Constructive interference

Question 29

Condition for destructive interference is when the path difference between two waves is equal to (m is an integer, n is the refractive index, lambda is the wavelength)

Answer 29

(M+1/2)/lambda

Question 30

In the condition for forming bright fringes, dsin(theta)=mlambda, 'd' represents the distance between the 2 slits and the screen

Answer 30

False

Question 31

A He-Ne laser beam (lambda=632.8nm) is incident on double slits of separation 0.8mm. On a screen located 6m from the slits, how far is the third order maximum from the center of the interference pattern?

Answer 31

14.2mm Y=m(lambda)L/d

Question 32

Two conditions for getting an interference fringe in youngs double slit experiment is

Answer 32

Monochromatic light and mutual coherence

Question 33

Thin film interference is based on the division of amplitude, true or false

Answer 33

True

Question 34

Which is commonly used single layer anti reflection coating material?

Answer 34

Magnesium fluoride

Question 35

Single layer anti reflection coating reduces light reflection from 4.3% to about _______

Answer 35

1.5%

Question 36

How much does a multilayer anti reflection thin film coating reduce the light reflection to about ?

Answer 36

0.5%

Question 37

The minimum thickness of an anti reflecting thin film on glass is _______ of the wavelength in the thin film

Answer 37

Quarter

Question 38

Diffraction is a change in direction of propagation due to

Answer 38

Edge phenomenon

Question 39

According to fresnel, whom expanded on huygen's principle, proposed that that the secondary wavelets would undergo mutual interference

Answer 39

True

Question 40

What is the condition for constructive interference in a single slit diffraction

Answer 40

Asin(theta)=m(lambda)

Question 41

In the single slit diffraction, when the aperture size 'a' decreases, what happens to the diffraction pattern

Answer 41

Spread out

Question 42

What is the type of diffraction, if the source of light and the screen are at a finite distance from the diffraction aperture

Answer 42

Fresnel diffraction

Question 43

The smallest letters that a person with 20/40 acuity can resolve have a detail that subtends at angle of ____

Answer 43

2'

Question 44

An optical device that blocks alternate zones is called

Answer 44

Zone plate

Question 45

What happens to diffraction image point in a pjhase plate when the alternate zones are phase shifted by 180

Answer 45

Brighter

Question 46

Incoherent scattering depends on what two conditions?

Answer 46

Particle size and distance between two particle ( it should be greater than coherence of the light)

Question 47

When the particles are smaller than wavelength of light, what type of scatterin

Answer 47

Rayleigh

Question 48

What is the scattering profile of rayleigh

Answer 48

All directions

Question 49

Shorter wavelength scatters more light, true or false

Answer 49

True, blue

Question 50

Corneal transmittance is dependent upon

Answer 50

Wavelength

Question 51

What is the effect of light transmission to blue rims for red light

Answer 51

1% because of absence of melanin 0.2% for green light

Question 52

What is the 3rd component for blue and green eyes in scatter other than scleral wall and iris?

Answer 52

Fundus

Question 53

As you age for a healthy non cataractous eye, what is the increase in scatter for age 77?

Answer 53

3x

Question 54

What percentage of horizontally polarizaed light gets transmitted if a vertically polarized filter is tilted 5 degrees?

Answer 54

Cos^2(theta) Cos^2(5) 8% Make sure to change to radians in calculator!!

Question 55

For light in air incident on high index plastic of 1.66 refractive index, what is the incident angle of polarization

Answer 55

Brewsters angle Tan(theta)=n2/n1 53.93 degrees

Question 56

The sunlight glare can pass through a polarized filter when the transmission axis is _______

Answer 56

Horizontal | -if you hold it vertical, you will stop the sunlight scatter

Question 57

The waggle dance of the bee communicates the direction of food and _____

Answer 57

Location

Question 58

Formed dichroism is based on specific property of material which is ______

Answer 58

Structure

Question 59

When light travels in birefringent material, a relative delay between transmission is called

Answer 59

Phase retardation

Question 60

What is the slow ray in polarization called

Answer 60

Extraordinary ray

Question 61

What is the fast ray in polarization called

Answer 61

Ordinary ray

Question 62

Due to birefringence of cornea and lens, it changes from linear polarization to ______

Answer 62

Elliptical

Question 63

Haidenger's brush apparatus could be used to diagnose mblyopia due to what

Answer 63

Eccentric target