A thin film having thickness t<<λ is seen in white light. It will appear (a) White (b) Red (c) Black (d) Violet

A thin film having thickness t<<λ is seen in white light. It will appear (a) White (b) Red
(c) Black (d) Violet
by

1 Answer

Answer :

(c) Black
by

Related questions

To observe interference in thin films with a light of wavelength λ, the thickness of the film (a) Should be much smaller than λ (b) Should be a few thousand times of λ (c) Should be of the order of λ (d) Should be of the order of nanometer

Description : To observe interference in thin films with a light of wavelength λ, the thickness of the film (a) Should be much smaller than λ (b) Should be a few thousand times of λ (c) Should be of the order of λ (d) Should be of the order of nanometer

Last Answer : (c) Should be of the order of λ

The interference in thin films is because (a) The film reflects some light (b) The film is thin enough so that refracted ray is close to reflected ray (c) The reflected ray undergo path change of λ/2 (d) All of above

Description : The interference in thin films is because (a) The film reflects some light (b) The film is thin enough so that refracted ray is close to reflected ray (c) The reflected ray undergo path change of λ/2 (d) All of above

Last Answer : (d) All of above

In case of thin film of non-uniform thickness, when illuminated with white light, the film appears colored. This is due to change of what factor? (a) Conditions for path difference at different points of film (b) Change in optical path difference at different points of film (c) Thickness of film is different at different points of film (d) All of above

Description : In case of thin film of non-uniform thickness, when illuminated with white light, the film appears colored. This is due to change of what factor? (a) Conditions for path difference at different points of ... of film (c) Thickness of film is different at different points of film (d) All of above

Last Answer : (d) All of above

A thin film is observed in white light. The color of the film seen at a particular point depends upon (a)Location of observer (b)Width of the source (c) Distance of the source (d) Brightness of the source

Description : A thin film is observed in white light. The color of the film seen at a particular point depends upon (a)Location of observer (b)Width of the source (c) Distance of the source (d) Brightness of the source

Last Answer : (a)Location of observer

A film is said to be thin if its thickness is (a) Much smaller than wavelength of light (b) Comparable with one wavelength of light (c) Of the order of nanometer (10-9 m) (d) Of the order of Pico meter (10-12 m)

Description : A film is said to be thin if its thickness is (a) Much smaller than wavelength of light (b) Comparable with one wavelength of light (c) Of the order of nanometer (10-9 m) (d) Of the order of Pico meter (10-12 m)

Last Answer : (b) Comparable with one wavelength of light

In interference experiment, by keeping all other parameters constant, if you see the thin film interference from different angles, you will observe (a)Uniform illumination of screen (b) Uniform darkness on the screen (c) Equally spaced dark and white bands (d) Few colored bands and then general illumination

Description : In interference experiment, by keeping all other parameters constant, if you see the thin film interference from different angles, you will observe (a)Uniform illumination of screen (b) Uniform ... c) Equally spaced dark and white bands (d) Few colored bands and then general illumination

Last Answer : (d) Few colored bands and then general illumination

What is the nature of interference pattern at the contact edge of wedge shaped film (a) Always bright (b) Always dark (c) Bright or dark depending upon the thickness of other end (d) Bright or dark depending upon the wavelength of the light

Description : What is the nature of interference pattern at the contact edge of wedge shaped film (a) Always bright (b) Always dark (c) Bright or dark depending upon the thickness of other end (d) Bright or dark depending upon the wavelength of the light

Last Answer : (b) Always dark

In reference with antireflection coating which of the following statement is true? A. Thickness of the film should be changed for light of same wavelength but different intensity B. Thickness of the film need not be changed for light of same wavelength but different intensity C. Thickness of the film should be increased for light of same wavelength but higher intensity D. Thickness of the film should be decreased for light of same wavelength but higher intensity

Description : In reference with antireflection coating which of the following statement is true? A. Thickness of the film should be changed for light of same wavelength but different intensity B. Thickness of ... D. Thickness of the film should be decreased for light of same wavelength but higher intensity

Last Answer : B. Thickness of the film need not be changed for light of same wavelength but different intensity

If you look perpendicular at thin film and move yourself away from the film (staying perpendicular to the film), you will notice (a) Reflected light becomes brighter and brighter (b) Reflected light becomes darker and darker (c) Reflected light alternates between darker and brighter (d) None of the Above

Description : If you look perpendicular at thin film and move yourself away from the film (staying perpendicular to the film), you will notice (a) Reflected light becomes brighter and brighter (b) Reflected ... and darker (c) Reflected light alternates between darker and brighter (d) None of the Above

Last Answer : (c) Reflected light alternates between darker and brighter

In Michelson interferometer semi silvered mirror is used To obtain __________. A. Thin film interference B. Phase coherence C. mono chromatic light D. colored fringe

Description : In Michelson interferometer semi silvered mirror is used To obtain __________. A. Thin film interference B. Phase coherence C. mono chromatic light D. colored fringe

Last Answer : B. Phase coherence

The conditions for the production of constructive and destructive interference are reversed due to the fact that on striking the thin film -------. A. Two rays of splitted light undergo phase change of 180° B. One of two rays of splitted light undergo phase change of 180° C. Light is diffracted, light is polarized

Description : The conditions for the production of constructive and destructive interference are reversed due to the fact that on striking the thin film -------. A. Two rays of splitted light undergo phase ... two rays of splitted light undergo phase change of 180° C. Light is diffracted, light is polarized

Last Answer : A. Two rays of splitted light undergo phase change of 180°

When a light wave suffers reflection at the interface between air and glass medium, the change of wavelength of the reflected wave in air is equal to (a) 0 (b) λ/2 (c) λ (d) 2λ

Description : When a light wave suffers reflection at the interface between air and glass medium, the change of wavelength of the reflected wave in air is equal to (a) 0 (b) λ/2 (c) λ (d) 2λ

Last Answer : (b) λ/2

.In Rayleigh law of scattering ,The intensity of scattered light is proportional to A. λ B. λ -2 C. λ -4 D. λ-1

Description : .In Rayleigh law of scattering ,The intensity of scattered light is proportional to A. λ B. λ -2 C. λ -4 D. λ-1

Last Answer : C. λ -4

A wedge shaped thin has (a) Non-uniform thickness (b) Zero thickness at one end and it increasing towards other end (c) Zero thickness at both ends (d) Thickness increase and decrease alternately

Description : A wedge shaped thin has (a) Non-uniform thickness (b) Zero thickness at one end and it increasing towards other end (c) Zero thickness at both ends (d) Thickness increase and decrease alternately

Last Answer : b) Zero thickness at one end and it increasing towards other end

A wedge shaped thin has A. Non-uniform thickness B. Zero thickness at one end and it increasing towards other end C. Zero thickness at both ends D. Thickness increase and decrease alternately

Description : A wedge shaped thin has A. Non-uniform thickness B. Zero thickness at one end and it increasing towards other end C. Zero thickness at both ends D. Thickness increase and decrease alternately

Last Answer : B. Zero thickness at one end and it increasing towards other end

In wedge shaped film the interference pattern has nature (a) Parallel to the end where thickness is non-zero (b) Perpendicular to contact edge (c) Parallel to contact edge (d) Perpendicular to the end where thickness is non-zero

Description : In wedge shaped film the interference pattern has nature (a) Parallel to the end where thickness is non-zero (b) Perpendicular to contact edge (c) Parallel to contact edge (d) Perpendicular to the end where thickness is non-zero

Last Answer : (c) Parallel to contact edge

Why in Newton’s rings the center spot is always dark? A. The thickness of the film is zero at center B. The path difference between incident ray and reflected ray is ½wavelength C. The incident ray and reflected ray undergo destructive interference D. All of above

Description : Why in Newton’s rings the center spot is always dark? A. The thickness of the film is zero at center B. The path difference between incident ray and reflected ray is ½wavelength C. The incident ray and reflected ray undergo destructive interference D. All of above

Last Answer : D. All of above

Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the thin film is replaced by the film of higher refractive index. What will be the effect on bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will merge (d) There will not any effect

Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the thin film is replaced by the film of higher refractive index. What will be the effect on bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will merge (d) There will not any effect

Last Answer : (b) Bandwidth decreases

What is the nature of interference pattern for thin film of wedge shaped (a) Concave outside (b) Convex outside (b) Equally spaced (d) Concave inside

Description : What is the nature of interference pattern for thin film of wedge shaped (a) Concave outside (b) Convex outside (b) Equally spaced (d) Concave inside

Last Answer : (b) Convex outside

Interference in thin film is mainly because of (a) Division amplitude (b) Division of wave fronts (c) Addition of amplitude (d) Addition of wave fronts

Description : Interference in thin film is mainly because of (a) Division amplitude (b) Division of wave fronts (c) Addition of amplitude (d) Addition of wave fronts

Last Answer : (a) Division amplitude

What is the nature of interference pattern for thin film of wedge shaped A. Concave outside B. Convex outside C. Equally spaced D. Concave inside

Description : What is the nature of interference pattern for thin film of wedge shaped A. Concave outside B. Convex outside C. Equally spaced D. Concave inside

Last Answer : B. Convex outside

Interference in thin film is mainly because of A. Division amplitude B. Division of wave fronts C. Addition of amplitude D. Addition of wave fronts

Description : Interference in thin film is mainly because of A. Division amplitude B. Division of wave fronts C. Addition of amplitude D. Addition of wave fronts

Last Answer : A. Division amplitude

The path difference corresponding to a phase difference of π radian is __________. A.2λ B .λ/2 C .λ /4 D. λ

Description : The path difference corresponding to a phase difference of π radian is __________. A.2λ B .λ/2 C .λ /4 D. λ

Last Answer : B .λ/2

Resolving power of grating is given by A. λ/2 B. λ/dλ C. dλ/λ D. none of these

Description : Resolving power of grating is given by A. λ/2 B. λ/dλ C. dλ/λ D. none of these

Last Answer : B. λ/dλ

The fringe width and the angle of wedge are related to A. β=λ/2θ B. θ =λ/2 β C. β=λ/θ D. λ= β/2θ

Description : The fringe width and the angle of wedge are related to A. β=λ/2θ B. θ =λ/2 β C. β=λ/θ D. λ= β/2θ

Last Answer : A. β=λ/2θ

Interference pattern is observed in wedge-shaped film for monochromatic light. Now monochromatic light is replaced by white light. What will be the effect on interference pattern? (a) It will turn to dark (b) It will turn to bright (c) Bands will disappear (d) It will be a mixture of all colors

Description : Interference pattern is observed in wedge-shaped film for monochromatic light. Now monochromatic light is replaced by white light. What will be the effect on interference pattern? (a) It will turn to dark (b) It will turn to bright (c) Bands will disappear (d) It will be a mixture of all colors

Last Answer : (d) It will be a mixture of all colors

A slit of width ‘a’ is illuminated by white light. For what value of ‘a’ will the first minimum for red light fall at an angle of 300 wavelength of red light is 6500 A0 A. 1.1 x 10 -3 cm B. 1.4 X 10 -4 cm C. 1.3 X 10 -4 cm D. 1.6 X 10 -4 cm

Description : A slit of width ‘a’ is illuminated by white light. For what value of ‘a’ will the first minimum for red light fall at an angle of 300 wavelength of red light is 6500 A0 A. 1.1 x 10 -3 cm B. 1.4 X 10 -4 cm C. 1.3 X 10 -4 cm D. 1.6 X 10 -4 cm

Last Answer : C. 1.3 X 10 -4 cm

The region of the electromagnetic spectrum immediately above the frequencies to which the human eye is sensitive is called: A. I r B. ultra-violet C. r f D. gamma ray

Description : The region of the electromagnetic spectrum immediately above the frequencies to which the human eye is sensitive is called: A. I r B. ultra-violet C. r f D. gamma ray

Last Answer : B. ultra-violet

What is the highest order spectrum which may be seen with monochromatic light of wavelength 5000 A0by means of diffraction grating with 5000 lines/cm? A. 2 B. 4 C. 8 D. 16

Description : What is the highest order spectrum which may be seen with monochromatic light of wavelength 5000 A0by means of diffraction grating with 5000 lines/cm? A. 2 B. 4 C. 8 D. 16

Last Answer : B. 4

A grating has 6000 lines per cm. How many orders of light of wavelength 4500 A 0 can be seen? A. 1 B. 2 C. 3 D. 4

Description : A grating has 6000 lines per cm. How many orders of light of wavelength 4500 A 0 can be seen? A. 1 B. 2 C. 3 D. 4

Last Answer : C. 3

Colors in thin films are because of A. Dispersion C. Interference B. Compton effect D. Diffraction

Description : Colors in thin films are because of A. Dispersion C. Interference B. Compton effect D. Diffraction

Last Answer : C. Interference

In interference experiment, monochromatic light is replaced by white light, we will see (a) Uniform illumination of screen (b) Uniform darkness on the screen (c) Equally spaced dark and white bands (d) Few colored bands and then general illumination

Description : In interference experiment, monochromatic light is replaced by white light, we will see (a) Uniform illumination of screen (b) Uniform darkness on the screen (c) Equally spaced dark and white bands (d) Few colored bands and then general illumination

Last Answer : (d) Few colored bands and then general illumination

Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced to zero. What will be the effect on Bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will disappear (d) There will not any effect

Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced to zero. What will be the effect on Bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will disappear (d) There will not any effect

Last Answer : (c) Bands will disappear

Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced. What will be the effect on bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will disappear (d) There will not any effect

Description : Interference pattern is observed in wedge-shaped film and bandwidth is noted. Now the angle of wedge is reduced. What will be the effect on bandwidth? (a) Bandwidth increases (b) Bandwidth decreases (c) Bands will disappear (d) There will not any effect

Last Answer : B) BANDWIDTH DECREASES

Find the maximum value of resolving power of a grating 3 cm wide having 5000 lines per cm, if the wavelength of light used is 5890 A0. A. 40000 B. 45000 C. 4500 D. 5000

Description : Find the maximum value of resolving power of a grating 3 cm wide having 5000 lines per cm, if the wavelength of light used is 5890 A0. A. 40000 B. 45000 C. 4500 D. 5000

Last Answer : a option

Light is normally incident on a thin soap film and is reflected. If the wavelength of this light is "L" and the index of refraction of the soap film is "N", complete destructive interference will occur for a film thickness of: w) L / 8N x) L / 4N y) L / 2N z) 3L / 4N

Description : Light is normally incident on a thin soap film and is reflected. If the wavelength of this light is "L" and the index of refraction of the soap film is "N", complete destructive interference will occur for a film thickness of: w) L / 8N x) L / 4N y) L / 2N z) 3L / 4N

Last Answer : ANSWER: Y -- L / 2N 

Newton’s rings are formed because of interference between the light Reflected from (a) Upper surface of Plano-convex lens and lower surface of plane glass plate (b) Lower surface of Plano-convex lens and upper surface of plane glass plate (c) Lower and upper surface of Plano-convex (d) Lower and upper surfaces of plane glass plate

Description : Newton's rings are formed because of interference between the light Reflected from (a) Upper surface of Plano-convex lens and lower surface of plane glass plate (b) Lower surface of Plano-convex ... c) Lower and upper surface of Plano-convex (d) Lower and upper surfaces of plane glass plate

Last Answer : (b) Lower surface of Plano-convex lens and upper surface of plane glass plate

Why in Newton’s rings setup, the beam splitter (mirror) is kept at 450? (a) It allows light rays to incident at 450over the top surface of Plano convex lens (b) It allows light rays to incident uniformly over the top surface of Plano convex lens (c) It allows light rays to incident parallel over the top surface of Plano convex lens (d) It allows light rays to incident at 900over the top surface of Plano convex lens

Description : Why in Newton's rings setup, the beam splitter (mirror) is kept at 450? (a) It allows light rays to incident at 450over the top surface of Plano convex lens (b) It allows light rays to ... Plano convex lens (d) It allows light rays to incident at 900over the top surface of Plano convex lens

Last Answer : (d) It allows light rays to incident at 900over the top surface of Plano convex lens

Newton’s light illustrate the phenomenon of (a) Interference (b) Diffraction (c) Dispersion (d) Polarisation

Description : Newton’s light illustrate the phenomenon of (a) Interference (b) Diffraction (c) Dispersion (d) Polarisation

Last Answer : (a) Interference

In Newton’s rings experiment, if monochromatic source of light is replaced by another monochromatic source of higher wavelength. What will be the effect on radius (or diameter)? (a) Radius (or diameter) will decrease (b) Radius (or diameter) will increase (c) There will be no effect (d) Radius (or diameter) will remain constant but there will be more brightness

Description : In Newton's rings experiment, if monochromatic source of light is replaced by another monochromatic source of higher wavelength. What will be the effect on radius (or diameter)? (a) Radius (or ... be no effect (d) Radius (or diameter) will remain constant but there will be more brightness

Last Answer : (b) Radius (or diameter) will increase

When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to (a) 0 (b) π (c) 2π (d) π/2

Description : When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to (a) 0 (b) π (c) 2π (d) π/2

Last Answer : (b) π

The number of lines on plane gratings is 5000. If it is illuminated by a wavelength of light 6000 A0, how many orders will be visible? A. 3 B. 3.33 C. 4 D. 2.0

Description : The number of lines on plane gratings is 5000. If it is illuminated by a wavelength of light 6000 A0, how many orders will be visible? A. 3 B. 3.33 C. 4 D. 2.0

Last Answer : A. 3

What is true for intensity of scattered light according to Rayleigh’s law? A. The intensity for scattering for light of largest wavelength more B. The light of smallest wavelength will be scattered more C. All the wavelengths are scattered equally D. Intensity of light is not affected by scattering

Description : What is true for intensity of scattered light according to Rayleigh's law? A. The intensity for scattering for light of largest wavelength more B. The light of smallest wavelength will be scattered ... C. All the wavelengths are scattered equally D. Intensity of light is not affected by scattering

Last Answer : B. The light of smallest wavelength will be scattered more

Diffraction due to circular aperture If a light passes through a small pinhole, and incident on a screen. What will be observed on the screen? A.A sharp bright point of the width equal to width the pinhole B. A bright point of the width equal to width the pinhole but of less intensity C. A bright ring at the centre surrounded by alternate dark and bright rings D. A diffused bright point

Description : Diffraction due to circular aperture If a light passes through a small pinhole, and incident on a screen. What will be observed on the screen? A.A sharp bright point of the width equal to ... A bright ring at the centre surrounded by alternate dark and bright rings D. A diffused bright point

Last Answer : C. A bright ring at the centre surrounded by alternate dark and bright rings

Antireflection coating is helps in which case of the following? A. Minimizing the reflection of light from top surface B. To absorb and control the amount of light entering into the medium C. To allow maximum light to reflect from top surface D. To allow minimum light to enter into the medium

Description : Antireflection coating is helps in which case of the following? A. Minimizing the reflection of light from top surface B. To absorb and control the amount of light entering into the medium C. To allow maximum light to reflect from top surface D. To allow minimum light to enter into the medium

Last Answer : A. Minimizing the reflection of light from top surface

When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to A. 0 B. π C.2 π D.π /2

Description : When a light wave suffers reflection at the interface between air and glass medium, the change of phase of the reflected wave in air is equal to A. 0 B. π C.2 π D.π /2

Last Answer : B. π

When Newton’s rings interference pattern is viewed from above by means of reflected light, the central spot is __________. A. Dark B. Multi colored C. Bright D. None of these

Description : When Newton’s rings interference pattern is viewed from above by means of reflected light, the central spot is __________. A. Dark B. Multi colored C. Bright D. None of these

Last Answer : A. Dark

__________ of the following phenomenon cannot be explained on the particle nature of light. A. Photo Electric Effect B. Compton’s Effect C. Pair Production D. Interference

Description : __________ of the following phenomenon cannot be explained on the particle nature of light. A. Photo Electric Effect B. Compton’s Effect C. Pair Production D. Interference

Last Answer : A. Photo Electric Effect

Two sources of light are said to be coherent if __________. A. they produce waves of the same wave length B. they have the same amplitude of vibration C. they produce waves in the medium simultaneously D. they produce waves of the same amplitude

Description : Two sources of light are said to be coherent if __________. A. they produce waves of the same wave length B. they have the same amplitude of vibration C. they produce waves in the medium simultaneously D. they produce waves of the same amplitude

Last Answer : D. they produce waves of the same amplitude