WorksheetsCh-10 Wave optics
Total questions: 102
Worksheet time: 54mins
What happens if one of the slits, say S1 in Young’s double slit experiment, is covered with a glass plate which absorbs half the intensity of light from it?
The bright fringes become less-bright and the dark fringes have a finite light intensity
The bright fringes become brighter and the dark fringes become darker
The fringe width decreases
No fringes will be observed
What happens to the interference pattern the two slits S1 and S2 in Young’s double experiment are illuminated by two independent but identical sources?
The intensity of the bright fringes doubled
The intensity of the bright fringes becomes four times
Two sets of interference fringes overlap
No interference pattern is observed
What is the reason for your answer to the above question?
The two sources do not emit light of the same wavelength
The two sources emit waves which travel with different speeds
The two sources emit light waves of different amplitudes
There is not constant phase difference between the waves emitted by the two sources
Two sources of light are said to be coherent when both give out light waves of the same:
amplitude and phase
intensity and wavelength
speed
wavelength and a constant phase difference
Which of the following is conserved when light waves interference?
phase
intensity
amplitude
none of these
An optically active compound
rotates the plane of polarised light
changes the direction of polarised light
does not allow plane polarised light to pass through
none of these
Which among the following isn’t a suitable phenomenon to establish that light is wave motion?
Interference
Diffraction
Reflection
Polarization
The locus of all particles in a medium, vibrating in the same phase is called
wavelet
fringe
Wavefront is the locus of all points, where the particles of the medium vibrate with the same
phase
amplitude
frequency
period
When light suffers reflection at the interface between water and glass, the change of phase in the reflected wave is
zero
π
π/2
2π
Two sources of light are said to be coherent, when they give light waves of same
amplitude and phase
wavelength and constant phase difference
intensity and wavelength
phase and speed
What is the Brewster's angle for air to glass transition? (μ_ag = 1.5)
tan (1.5)
sin (1.5)
sin⁻¹ (1.5)
tan⁻¹ (1.5)
When ordinary light is made incident on a quarter wave plate, the emergent light is
linearly polarised
circularly polarised
unpolarised
elliptically polarised
Unpolarized light is incident on a plane glass surface. The angle of incidence so that reflected and refracted rays are perpendicular to each other, then
tan iₚ = μ/2
tan iₚ = μ
sin iₚ = μ
cos iₚ = μ
To observe diffraction, the size of the obstacle
should be X/2, where X is the wavelength.
should be of the order of wavelength.
has no relation to wavelength.
should be much larger than the wavelength.
In Young’s double-slit experiment, the phase difference between the light waves reaching the third bright fringe from the central fringe will be
2π
4π
6π
8π
The colours on the soap bubble is due to
Interference
Diffraction
Polarisation
Reflection
Which of the following statements indicates that light waves are transverse?
Light waves can be polarised
Light waves can show interference
Light waves undergo diffraction
They travel in the vacuum
Which of the following phenomenon is not explained by Huygen’s wave theory?
Diffraction
Polarisation
Photoelectric effect
Interference
Bending of Light phenomena is shown by
Polarization
Diffraction
Interference
Dispersion
An optically active compound
rotates the plane of polarised light
changes the direction of polarised light
does not allow plane polarised light to pass through
none of these
To observe diffraction, the size of the obstacle
should be X/2, where X is the wavelength.
should be of the order of wavelength.
has no relation to wavelength.
should be much larger than the wavelength.
In Young’s double slit experiment, the fringe width is β. If the entire arrangement is now placed inside a liquid of refractive index μ, the fringe width will become
μβ
β/μ
β/μ+1
β/μ−1
In the phenomena of Diffraction of light when the violet light is used in the experiment instead of red light then.
Fringe width increases
No change in fringe width
Fringe width decreases
Colour pattern is formed
In the Young’s double slit experiment both the slits are similar. If the length of one of the slits is halved, which of the following is true?
Bright fringes become narrower.
Bright fringes become wider.
Dark fringes become darker.
Dark fringes become brighter.
Instead of using two slits as in Young’s experiment, if we use two separate but identical sodium lamps, which of the following occur?
general illumination
widely separate interference
very bright maximum
very dark minimum
In an interference pattern produced by two identical slits, the intensity at the site of maxima is I. When one of the slit is closed, the intensity at the same spot is I₀. What is the relation between I and I₀?
I = 2 I₀
I = 4 I₀
I = 16 I₀
I = I₀
Ratio of intensities of two waves are given by 4 : 1. Then the ratio of the amplitudes of the two waves.
2 : 1
4 : 1
1 : 2
1 : 4
The speed of light in air is 3 × 10^8 m/s. If the refractive index of glass is 1.5, find the time taken by light to travel a distance 50 cm in glass.
2.5 × 10^-9 sec.
0.5 × 10^{-9} sec.
0.16 × 10−9 sec.
3 × 10^{-9} sec.
In a double slit interference pattern, the first maxima for infrared light would be
at the same place as the first maxima for green light
closer to the centre than the first maxima for green light
farther from the centre than the first maxima for green light
infrared light does not produce an interference pattern
In the Young double slit experiment, the fringe pattern as seen on the screen is:
Parabola
Hyperbola
Ellipse
Spiral
The light sources used in Young’s double slit experiment are:
Incoherent
Coherent
White light
Blue-green-red Light.
If the width of the slit in single slit diffraction experiment is doubled, then the central maximum of diffraction pattern becomes:
broader and brighter
broader and fainter
sharper and fainter
sharper and brighter
Angular width of interference fringe depends on
Distance Between Slit and Screen
Ratio of the wavelength and Slit width
Wavelength of light
Width of Slit
In a Young’s double slit experiment, the separation between the slits is 0.1 mm, the wavelength of light used is 600nm and the interference pattern is observed on a screen 1m away. Find the separation between bright fringes.
6.0 mm
6.6 mm
6 m
60 cm
The wave-front due to source situated at the infinity is
(a)
What is the effect on the angular width of interference fringes in a Young’s double slit experiment when the screen moved near to the plane of slits?
constant
increases
decreases
not defined
Huygens wave theory allows us to know
The wavelength of the wave
The velocity of the wave
The amplitude of the wave
The propagation of wave-fronts
Two monochromatic light beams intensities of I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are
5I and I
5I and 3I
9I and I
9I and 3I
The phenomenon of diffraction can be treated as interference phenomenon. If the number of coherent sources is:
one
two
zero
infinity
Colours appears on a thin film of soap and a soap bubble is due to
Interference
Diffraction
Polarisation
Refraction
According to Huygens, medium through which light travel is
vacuum only
luminiferous ether
liquid only
solid only
In interference pattern, the energy is
created at maximum
destroyed at minimum
conserves but re-disturbed
none of the above
Coherence is a measure of
capability of producing interference by waves
waves being diffracted
waves being reflected
waves being refracted
The condition for Fraunhoffer diffraction from a single slit is that the light wave-front incident on a slit should be
Spherical
Cylindrical
Plane
Rectangular
In a Young’s double slit experiment, the separation between the slits is 0.1 mm, the wavelength of light used is 600nm and the interference pattern is observed on a screen 1m away. Find the separation between bright fringes.
6.6 mm
6.0 mm
6 mm
60 cm
In YDSE, The distance between two consecutive bright and dark fringes are given by:
β=λD/d
β=λ/d/D
β=λDd
β=λ/Dd
In the Young double slit experiment, the fringe pattern as seen on the screen is:
parabola
Hyperbola
Ellipse
Spiral
What is the effect on the angular width of interference fringes in a Young’s double slit experiment when the screen moved near to the plane of slits.
increases
decreases
constant
not defined
Bending of Light phenomena is shown by
Polarization
Diffraction
Interference
Dispersion
In the phenomena of Diffraction of light when the violet light is used in the experiment is used instead of red light then,
Fringe width increases
No change in fringe width
Fringe width decreases
Colour pattern is formed
Diffraction aspect is easier to notice in case of the sound waves than in case of the light waves because sound waves have longer wavelengths.
Sound waves travel faster than light waves.
Light waves have shorter wavelengths than sound waves.
Sound waves can be heard but light waves cannot.
The wave-front due to source situated at the infinity is
Spherical
Plane
Cylindrical
Rectangular
Colours appears on a thin film of a soap and a soap bubble is due to
Diffraction
Refraction
Dispersion
Interference
For an aperture of size (d) illuminated by a parallel beam of light having wavelength λ. The Fresnel’s distance
Z = d²/λ
Z = d/λ
Z = λ/d²
Z = λ/d
Angular width of interference fringe depends on
Distance Between Slit and Screen
Wavelength of light
Ratio of the wavelength and Slit width
Width of Slit
The phase difference between two waves at the place of constructive interference is given as a multiple of:
multiple of π
multiple of (2n-1)π
even multiple of π
odd multiple of π
The path difference between two waves at the place of destructive interference is given by:
multiple of λ
multiple of λ/2
even multiple of λ/2
odd multiple of λ/2
The light sources used in Young’s double slit experiment are
Incoherent
Coherent
White light
Blue-green-red Light.
What happens to the interference pattern the two slits S₁ and S₂ in Young’s double experiment are illuminated by two independent but identical sources?
The intensity of the bright fringes doubled
The intensity of the bright fringes becomes four times
Two sets of interference fringes overlap
No interference pattern is observed
What type of wave front will emerge from any distant source of light?
Spherical wave front
Cylindrical wave front
Plane wave front
None of these
How does the angular separation between fringes in single slit diffraction experiment change when the distance of separation between the slit and screen is doubled?
Becomes twice
Remains same
Becomes half
Becomes one-fourth
In Young’s double slit experiment, the fringe width is found to be 0.4 mm. If the whole apparatus is immersed in water of refractive index 4/3 without disturbing the geometrical arrangement, the new fringe width will be:
0.3 mm
0.4 mm
0.53 mm
0.75 mm
A screen is placed 50m from a single slit, which is illuminated with 6000Å light. If the distance between the first and third minima in the diffraction pattern is 3.00mm, what is the width of the slit?
200 μm
300 μm
250 μm
350 μm
How does the fringe width alter, if the entire Young’s double slit experimental set up is completely immersed into water?
Increases
Decreases
Remains same
None of these
When tiny circular obstacle is placed in the path of light from a distance source, a bright spot is seen at the centre of the obstacle. It happens due to
Polarization of light waves
Diffraction of light waves
Interference of light waves
Scattering of light waves
The interference phenomenon takes place
In all waves
In transverse waves only
In longitudinal waves only
In standing waves only
In Young’s double slit experiment, using sodium light (λ = 5898), 92 fringes are seen. If given color (λ = 5461) is used, how many fringes will be seen?
(a)
In the diffraction pattern due to single slit, at the position of 2nd maximum the path difference between the wavelets from the opposite edges of the slit is
5λ/2
3λ/2
2λ
λ
Two waves having intensities in the ratio of 9:1 produce interference. The ratio of the maximum to the minimum intensity is
9:1
4:1
1:2
1:3
Two sources of intensity I and 4I are used in an interference experiment. Find the intensity at points where waves from two sources superimpose with phase difference π/2.
4I
6I
5I
9I
When a compact disc is illuminated by a source of white light, colored lines are observed. This is due to
Interference
Diffraction
Dispersion
Refraction
In a YDSE experiment, a monochromatic source of light is used. The shape of the interference fringes formed on a screen is
Parabola
Hyperbola
Straight line
Circle
If I₀ is the intensity of principal maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled?
2I₀
4I₀
I₀
I₀/2
In the phenomenon of diffraction of light, when blue light is used in the experiment instead of red light, then
A wavefront of a wave has direction with wave motion
Parallel
Perpendicular
opposite
at any angle θ
What happen when we use white light in Young’s double slit experiment.
No interference pattern will form
white fringes will form
Central bright fringe will be white
Central fringe will be colored
The parameter of light wave which remain same after refraction
speed
frequency
wavelength
none of these
A plane wave passed through a convex lens than geometrical shape of emerging wavefront will be
plane
diverging spherical
converging spherical
none of these
Which field is more effective in electromagnetic waves?
Electric field
magnetic field
both electric and magnetic field
none of these
Two identical coherent waves each of intensity 2I₀ are producing interference pattern. What are the values of resultant intensity at a point of (1) Constructive interference (2) destructive interference?
8I₀ ; 0
2I₀ ; 0
0 ; 8I₀
2I₀ ; 4I₀
The colours of a soap bubble seen in sunlight is due to ……… And colour due to a prism appears due to …………
Interference of light; refraction of light
Dispersion of light; total internal reflection of light
Interference of light; polarization of light
Interference of light; dispersion of light
The ratio of intensities at minima to the maxima in young’s double slit experiment is 9 : 25. Find the ratio of the widths of two slits.
16 : 1
1 : 16
4 : 1
1 : 4
In Young’s double slit experiment, the fringe width is β. if the entire arrangement is placed in a liquid of refractive index n, then the fringe width becomes
n β
β /(n+1)
β /(n-1)
β /n
In an interference experiment, the spacing between successive maxima and minima is
λd / D
λD / d
dD / λ
λd / 4D
In Young’s double slit experiment, the two slits are separated by 1 mm and the screen is placed at 1 m away. It produces the second dark fringe at a distance of 2mm from the central fringe. The wavelength of monochromatic light used would be
1.3 x 10⁻⁶ m
2 x 10⁻⁶ cm
2 x 10⁻⁹ m
1.3 x 10⁻⁶ cm
If the 8th bright fringe of light of wavelength λ₁ coincides with the 9th bright fringe of light of the wavelength λ₂ in Young’s double slit experiment, then the possible wavelengths of visible light are
400nm and 450nm
425nm and 400nm
400nm and 425nm
450nm and 400nm
In Young’s double slit experiment slits are separated by 0.32mm, and screen is at 1.6m away. Then find out the least distance from the strongly bright fringe where the bright fringes of wavelengths as 800nm and 600nm are coinciding.
10mm
12mm
1.2mm
1.0mm
Two monochromatic light waves of amplitudes 3A and 2A interfering at a point having phase difference of 60°. The intensity of light at that point will be
5A²
13A²
7A²
19A²
Wavefront generated from a line source is
Cylindrical wavefront
Spherical wavefront
Plane front
Either a.) or b.)
Huygens theory could not explain
Reflection of light
Photoelectric effect
Interference of light
Diffraction of light
In Young’s double slit experiment, the central point on the screen is:
Bright
Dark
First bright and later dark
First dark and later bright
Angular width of central maxima of a single slit diffraction pattern is independent of
Slit width
Frequency of the light used
Wavelength of the light used
Distance between slit and screen
A young’s double slit experiment uses a monochromatic source. The shape of interference fringes formed on a screen is:
Parabola
Straight line
Circle
Hyperbola
The main condition for diffraction to be observed is
Size of obstacle should be much smaller than the wavelength of the wave
Size of obstacle should be much larger than the wavelength of the wave
Size of the obstacle should be comparable to the wavelength of the wave.
Polarization of light proves the :
corpuscular nature of light
quantum nature of light
Transverse wave nature of light
Longitudinal wave nature of light
Which of the following is conserved when light waves interfere?
Energy
Phase
Intensity
Amplitude
A diffraction pattern is obtained by using a beam of red light. What will happen if the red light is replaced by the blue light?
No change will take place.
Bands become broader and farther apart.
Bands disappear
Diffraction bands become narrower and crowded.
In a double slit interference pattern, the first maxima for infrared light would be
at the same place as the first maxima for green light
closer to the centre than the first maxima for green light
farther from the centre than the first maxima for green light
infrared light does not produce an interference pattern
In Young's double slit experiment, if the distance between the slits is increased, what happens to the fringe width?
Becomes undefined
Increases
Decreases
Remains constant
What is the condition for constructive interference in Young's double slit experiment?
Path difference = λ/2
Path difference = 2nλ
Path difference = nλ
Path difference = (n + 1/2)λ
In a single slit diffraction pattern, the first minimum occurs at an angle θ given by:
sin θ = 2λ/a
sin θ = λ/a
sin θ = 3λ/a
sin θ = λ/2a
