Interference Mcqs

NO 1

Questions Wave nature of light evidenced by

Option-A Photoelectric effect

2

Two sources are said to be coherent

Same wavelength

3

When a thin film of ol or soap bubble is illuminated with white light, multiple colours appears, This is due to

Diffraction

4

Condition for Destructive interfence pattern is

Path difference is even multiple of λ/2

5

Condition for Constructive interfence pattern Path difference is odd is multiple of λ/2

6

Light waves are

7 8 9 10 11

Which of the following does not supports the wave nature of light A phase difference of π between two interfacing beams is equivalent to path difference In reflected light the central fringe of Newtons Ring is In Transmitted light the central fringe of Newtons Ring is In Newtons ring, the diameter of bright ring is propotional to

Longitudinal waves Interference 2λ Dark Dark Odd natural number

12

Extended source is needed in

Young's double slit experiemnt

13

In interference with two coherant sources, the fringe width varies

Directly with wavelength

14

Interfernce occours in

Longitudinal waves only

15

Newton's rings are

Locus of points of equal thickness

16

In Newton's ring experiemnt, diameter of rings formed is praportional to

λ

17 18 19 20

21

One of the following phenomena cannot be explained by wave theory of light To demonstrate the phenomena of interference, we require two sources of which emits radiation of Which of the following interference is produced by the division of wavefront When a thin sheet of mica is introduced in the path of one of the interfacing beam, then the fringe width Young's Experiement proved that

Polarization Same frequency Fabry Perot Interferrometer Increases

Light consist of waves

22 23

24

25

26 27 28 29 30 31

In Fresnel's Biprism experiemt the central fringe is If Young's appratus is immersed in water, then the fringe width

Bright Increases

In Newton's ring experiement, the distance between lens and the plate is increased, the Increases order of the ring at a given point is In Young's double slit experiement, the monochromatic source of yellow light is replaced by red light, then Frige width will be An excessively thin film appears in reflected light In Newtons ring experiment, if the planconvex lens is replaced by Biconvex lens then, In antireflection coating wavelength is in the order of Air-Wedge fringes are always A path difference of 3λ/2 between two waves corresponds to the phase difference of Which of the following does not changes the refraction

Increases

White Width of fringes reduced to half of its origional value λ Circular 3π/2 Wavelength

32

For interference pattern

Width of dark and bright bands are equal

33

To observe colour in thin films, film must exposed to

Broad source

34

Width of fringes for wedge shape film changes with the increase of wedge angle

Increases

35

In Newton's ring expt. The air film is repalced Decreases by water film, then the diameter of the ring

36

In Newton's ring expt. Which properties are measured

37

When Newton's ring is observed under white Only first few coloured light, which of the following statement is true rings will be visible

38

Which of the following are coherant sources

39 40 41

Wavelength of light

A 60 W and A 100 W bulbs

The wave nature of light is manifested by the Interference phenomena called as The two sources are said to be coherent if Same wavelength the emitted wave exhibits The phase difference of wave at glass – air 0 interface is

42

In the interference pattern of two waves, the intensities are 9:1, so the ratio of maximum 2:01 to minimum intensities is

43

If a light wave travelling a distance‘t’ through a medium of refractive index ‘μ’ Path difference then the product ‘μt’ is associated with

44 45 46 47 48

In destructive interference pattern, the path difference is odd multiple of In constructive interference pattern, the path difference is even multiple of When t=0, the film is dark and thickness increases gradually, the results in appearance of If a film of large thickness is illuminated by a white light then it shows A very thick film is illuminated by a white light, the reflected light shows

λ/4 λ/4 Maxima and minima alternatively Interference pattern Presence of colors

49

For bright or dark fringes of any particular order, the path difference must be

50

The separation distance between two Width of fringes successive fringes (dark or bright) must be

51

If Plano-convex lens is replaced by Biconvex lens, then the converging power of Half lens become

52

The width of fringes reduces to half at

Maxima

53

The eyes are more sensitive to which wavelength of light

6000Ǻ

54

In interference pattern, all maxima have

Same intensity

55 56 57 58 59 60 61 62 63

In diffraction, the intensity of central maxima is In interference pattern, the fringes are equally spaced have In diffraction pattern, the fringes are not equally spaced have For constructive interference, the path difference is For destructive interference, the path difference is For constructive interference, the phase difference is For destructive interference, the phase difference is Interference is caused by superposition of ---- waves Which of the following changes in interference of light?

Constant

Minimum Different width Different width nλ (2n-1)λ/2 (2m-1)π (2m-1)π Two Velocity

64

When light traveling in air gets reflected from No phase change water surface, there is -----

65

When light traveling in air gets transmitted in No phase change water, there is -----

66

Division of wavefront can be achieved with

67 68

69

70 71 72 73

Extended sources

Refractive index of one medium with respect ˂1 to another cannot be Formation of colors in light reflected from or transmitted through soap films is due to the Interference phenomena of ---- light If the refractive index of the medium of a wedge shaped film increases, fringe width --- Increases -In Newton's ring experiment, as we move away from center the fringe width---------The diffraction is divided into two different categories In Fraunhofer diffraction, the diffracted wavefront is In Fresnel diffraction, the diffracted wavefront is

Increases Fresnel Plane Plane

74

For first minimum, the order of spectrum is

One

75

The bending property of light at the sharp edge of the obstacle is

Interference

76

In Fraunhofer diffraction at circular aperature, the radius of central disc is

Independent on diameter of aperature

77 78 79 80 81 82 83 84 85

86

Slit to screen distance is finite in -----diffraction Slit to screen distance is infinite in -----diffraction Source to slit distance is finite in --diffraction Source to slit distance is Infinite in --diffraction In Fresnel diffraction, the wavefront incident on slit is --In Fraunhofer diffraction, the wavefront incident on slit is --Light eneters the geometrical shadow of slit in --Diffraction of light manifest its --- nature

Fresnel Fresnel Fresnel Fresnel Spherical Spherical Fresnel Particle

There is path difference between the rays coming from a source before entering the Fresnel slit in -There is no path difference between the rays coming from a source before entering the Fraunhofer slit in --

87

To observe the diffraction pattern lenses are Fraunhofer required in

88

A line on diffraction grating is

89

In Fraunhofer diffraction at a single slit, as slit Come closer width decreased , the adjecent minima

90

Which of the following depends on the total number of lines on the grating

Intensity of principal maxima

91

Which orders of maxima cannot be absent in the diffraction pattern of any grating

0

92

Which of the following depends on grating element

Position of principal maxima

93

Scattering of light by very small particles can Reflection be considered to be a special case of

94 95

Diffraction appears if the size of obstacle in path of rays is the order of In a single slit experiments, if the slit width is reduced

An opaque space

1 mm Fringes becomes brighter

Option-B Interference Same amplitude Polarization

Option-C Black body radiation Constant phase diffeence

Option-D Nuclear emission

Correct Option B

All of the above

D

Total Internal Reflection

Interference

D

Path difference is odd Path difference is Integral None of the above multiple of λ/2 multiple of λ/2

B

Path difference is even Path difference is Integral None of the above multiple of λ/2 multiple of λ/2

B

Transverse waves

Both A and B

None of the above

C

Polarization

Compton effect

Diffraction

C

λ

λ/2

None of the above

C

Non-uniform

Bright

None of the above

A

Non-uniform

Bright

None of the above

C

Natural number

Even natural number

Square root of natural number

D

Biprism Experiment

Newton's ring experiment None of the above

Inversly with wavelength

Directly with separation between slits

Inversly with distance between slits and screen

A

Transverse wave only

Electromagnetic wave only

All of the above

D

Locus of points of equal Inclination

Locus of points of equal Neither A or B thickness and Inclination

λ2

Square root of λ

Inversly praportional to square root of λ

C

Diffraction

Photoelectric effect

Interference

C

Nearly the same frequency

Same frequency and have a definite phase relationship

Different wavelength

C

Michelson's Interferrometer

Newton's ring

Fresnel's Biprism

D

Decreases

Remains Unchanged

None of the above

C

Light consist of particles

Light neither particle nor wave

Light is both particle and a wave

A

C

A

Dark

First dark then bright

First bright then dark

A

Decreases

Remains Unchanged

None of the above

B

Decreases

Remains Unchanged

Fringe pattern disappears

C

Decreases

Unchanged

Fringe pattern disappears

A

Black

Red

Yellow

B

Width of fringes Width of fringes remains increases to double of same its origional value

None of these

A

λ/2

λ/4

2λ

C

Spherical

Cylindrical

Straight

D

π/3

3π

2π/3

C

Frequency

Velocity

Intensity

B

Width of dark and bright bands are Unequal

Width of bright bands are None of these lesser than dark band

A

Point source

Either A or B

None of the above

A

Decreases

Remains same

Difficult to say

B

Increases

Remains same

None of the above

A

Thickness of the film

Refractive index of liquid All of the above

D

All clooured rings will be visible

All rings will disappears

None of the above

A

Two bulbs each of 60 Watt

Two halves of a 60 Watt bulbs

Virtual sources obtained by a Biprism

A

Diffraction

Reflection

Refraction

A

same amplitude

Constant phase difference

All of above.

D

π/2

π/4

π

A

9:01

3:01

4:01

D

Phase difference

Optical path

None of the above

C

λ/2

λ

2λ

B

λ/2

λ

2λ

B

Maxima and minima simultaneously Maxima

Minima

A

No interference pattern Diffraction pattern

None of the above

B

No colors

No any pattern

None of the above

B

Increases

Decreases

None of the above

A

Band width

Fringe width

None of the above

C

Doubled

Multiple order

None of the above

B

Minima

Central dark spot

Central bright spot

C

6500 Ǻ

5500 Ǻ

5890 Ǻ

C

Lower intensity

Higher intensity

None of the above

A

Maximum

No intensity

None of the above

B

Same width

Average width

None of the above

B

Same width

Average width

None of the above

A

(2n-1)λ/2

(2n-1)π

2nπ

A

nλ

(2n-1)π

2nπ

A

2mπ

mλ

(2m-1)λ/2

B

2mπ

mλ

(2m-1)λ/2

A

Three

Four

Any Number of

D

Frequency

Wavelength

None of the above

D

Phase change of π/2

Phase change of π/4

Phase change of π

D

Phase change of π/2

Phase change of π/4

Phase change of π

A

Point sources

Both A and B

Neither A or B

C

>1

1.5

None of the above

D

Diffraction

Polarization

Scattering

A

Decreases

Remains same

First increases and then decreases

B

Decreases

Remains same

First increases and then decreases

B

Fraunhofer

Fresnel and Fraunhofer

None of the above

C

Spherical

Cylindrical

None of the above

A

Spherical

Either spherical or cylindrical

None of the above

C

Two

Three

None of the above

A

Dispersion

Diffraction pattern

Polarization

C

Large as the diameter Small as the diameter of of aperature is large aperature is large

None of these

C

Fraunhofer

Both A and B

None of the above

A

Fraunhofer

Both A and B

None of the above

B

Fraunhofer

Both A and B

None of the above

A

Fraunhofer

Both A and B

None of the above

B

Cylindrical

A or B

Plane

C

Cylindrical

A or B

Plane

D

Fraunhofer

Both A and B

None of the above

C

Wave

Dual nature

None of the above

B

Fraunhofer

Both A and B

None of the above

A

Fresnel

Both A and B

None of the above

A

Fresnel

Both A and B

None of the above

A

A slit

A slit and an opaque space

None of the above

C

Move Apart

Remains at fixed position

Increases initailly and then decraeses

B

Intensity of minima

Position of principal maxima

Position of minima

A

1

2

0 and 1

D

Position of minima

Maximum order

All above

D

Refraction

Interefernce

Diffraction

D

10-4 mm

0.1 mm

1 cm

B

Fringes become narrower

Fringes become wider

Colour of fringes change

B

Topic Interference Interference Interference

Interference

Interference Interference Interference Interference Interference Interference Interference Interference Interference Interference Interference

Interference Interference Interference Interference Interference

Interference

Interference Interference

Interference

Interference

Interference Interference Interference Interference Interference Interference Interference Interference Interference

Interference Interference Interference

Interference Interference Interference Interference

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Interference Interference Interference Interference Interference Interference

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Interference Interference Interference Interference Interference Interference Interference Interference Interference Interference Interference Interference Interference

Interference Interference Interference Interference Interference

Interference

Interference Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction

Diffraction

Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction Diffraction