Processing math: 100%

CBSE Questions for Class 12 Medical Physics Wave Optics Quiz 10 - MCQExams.com

Angular width of  central maximum of a diffraction pattern on a single does not depend upon :
  • Distance between slit and source
  • Wavelength of the light used
  • width of the slit
  • None of the above
In Young's double slit experiment 10th order maxima is obtained at the point of  observation in the interference pattern for λ=7000Ao. If the source is replaced by another one of wavelength 5000 Ao  then the order of maximum at the same point will be 
  • 12 th
  • 14 th
  • 16 th
  • 18 th
A parallel beam of monochromatic light of wavelength 5000 A is incident on a single narrow slit of width 0.001 mm. The light is focussed by a convex lens on a screen placed on focal plane. The first minimum will be formed formed for the angle of diffraction equal to 
  • 20
  • 15
  • 30
  • 50
Two coherent source must have the same :
  • amplitude
  • phase difference
  • frequency
  • both B and C
A monochromatic light is incident on a single slit of width 24×105 cm. Calculate wavelength of light if angular position of 1st secondary maxima is 30o.
  • 8000 Ao
  • 12000 Ao
  • 6000 Ao
  • 16000 Ao
A slit of size 0.15cm is placed at 2.1m from a screen. On illuminated it by a light of wavelength 5×105cm. The width of diffraction pattern will be:-
  • 70nm
  • 0.14nm
  • 1.4nm
  • .014nm
A pale wavefront of wavelength λ is incident in a single slit of width a
  • λa
  • 2λa
  • aλ
  • a2λ
The first diffraction minimum due to single slit diffraction is θ, for a light of wavelength 5000A. If the width of the sit is 1×104, then the value of θ is
  • 300
  • 450
  • 600
  • 150
Two identical coherent sources placed on a diameter of a circle of radius R at separation x(<<R) symmetrically about the centre of the circle. The sources emit identical wavelength λ each. The number of points on the circle with maximum intensity is (x=5λ)
  • 20
  • 22
  • 24
  • 26
In an interference pattern of two waves fringe width is β. If the frequency of source is doubled then fringe width will become:-
  • 12β
  • β
  • 2β
  • 32β
In Y.D.S.E. If the width of the slits are gradually decreased, then 
  • Bright fringe will become brighter and dark fringe become darker
  • Bright fringe become less bright and dark fringe becomes less dark
  • Bright fringe become brighter and dark fringe become lighter
  • Bright fringe become less bright and dark fringe becomes less darker
A light source of diameter 2cm is placed 20cm behind a circular opaque disc to diameter 4cm. Shadow is formed on a screen at a distance of 80cm, the ratio of the area of umbra and penumbra shadow region is equal to 
1247750_154796be95ba40dd9145370da2559406.png
  • 0.58
  • 0.22
  • 0.18
  • 0.11
Angle of incidence is equal to the angle of reflection.
  • Always
  • Sometimes
  • Under special condition
  • Never
The wave theory of light was given by
  • HUygen
  • Young
  • Maxwell
  • Olank
In YDSE, d = 2 mm, D = 2 m andλ  = 500 nm. If intensity of two slits are l0 and 9l0 then find intensity at  y=16
  • 7l0
  • 10l0
  • 16l0
  • 4l0
The displacement of the interfering sound waves are y1=4sincot and y2=3sin(cot+π2). What is the amplitude of the resultant wave
  • 5
  • 7
  • 1
  • 0
Light of wavelength λ is incident on a slit of width d. The resulting Diffraction pattern is observed on screen at a distance D. the linear width of the principle maximum is then equal to width of the slit if D equals :
  • dλ
  • 2λd
  • d22λ
  • 2λ2d
Statement-1 : In standard YDSE set up with visible light, the position on screen where phase difference is zero appears bright.
and
Statement-2 : In YDSE set up magnitude of electromagnetic field at central bright fringe is not varying with time.
  • Statement-1 is true statement-2 is true and statement-2 is correct explanation for statement-1.
  • Statement-1 is true statement-2 is true and statement-2 is NOT the correct explanation for statement-1.
  • Statement-1 is true statement-2 is false.
  • Statement-1 is false statement-2 is true.
In a diffraction pattern due to a single slit of width a, the first minimum is observed at an angle 30 when light of wavelength 5000A is incident on the slit. The first secondary maximum is observed at an angle of
  • sin1(34)
  • sin1(14)
  • sin1(23)
  • sin1(12)
If light waves emitted by an ordinary source, for what period of time, the phase remains constant :-
  • 10sec
  • 1sec
  • 103 sec
  • 108 sec
If I0 is the intensity of the principal maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled
  • I0
  • I02
  • 2I0
  • 4I0
The main difference in the phenomenon of interference and diffraction is that:-
  • diffraction is due to interaction of light from the same wavefront whereas interference is the interaction of (light) waves from two isolated source.
  • diffraction is due to interaction of light from same wavefront whereas interference is the interaction of two waves derived from the same source.
  • diffraction is due to interaction of waves derived from the same source, whereas the interference is the bending of light from the same waveform
  • diffraction is caused by the reflected waves from a source whereas interference is caused due to waves from a source
Two point source separated by d=5μm emit light of wavelength λ=2μm in phase. A circular wire of radius 20 mum is placed around the source as shown in figure.
1281396_d07fc85051ff4bb6bc189c1ecea09d8e.png
  • Points A and B are dark and points C and D are bright.
  • Points A and B are bright and points C and D are dark.
  • Points A and C are dark and points B and D are bright.
  • Points A and C are bright and points B and D are dark.
A plane wave front of wave length 6000A is incident  upon a slit of 0.2mm width, which enables fraunhofer's diffraction pattern to be obtained on a screen 2m away. Width of the central maxima in mm will be 
  • 10
  • 12
  • 8
  • 2
Parallel beam is
  • produced by a source at infinity
  • produced by a source at finite distance
  • produced by a virtual source
  • None of these
What is the path difference of destructive interference :
  • nλ
  • n(λ+1)
  • (n+1)λ2
  • (2n+1)λ2
In diffraction using single slit, a slit of width a is illuminated by white light.  For red light (λ=6500A), the first minima is obtained for θ=30. Then the value of a will be:
  • 3250 A
  • 6.5×104
  • 1.24 μm
  • 2.6×104
Newton's corpuscular model of light.
  • successfully explain the rectilinear propagation of light, reflection of light and refraction of light
  • does not explain the phenomena of interference of light, diffraction of light and polarisation of light
  • is based upon particle theory of light
  • None of the above
In the case of parallel beam,
  • intensity gradually increases
  • intensity gradually decreases
  • intensity remains constant
  • None of these
According to Huygen's theory of light
  • light is stream of photon
  • light is wave
  • light behaves as particle
  • None of the above
What will be the angular width of central maxima in Fraunhoffer diffraction when light of wavelength 6000 ˚A is used and slit width is 12 ×105 cm.
  • 2 rad
  • 3 rad
  • 1 rad
  • 8 rad
The bending of beam of light around corners of obstacles is called
  • Reflecton
  • Diffraction
  • Refraction
  • Interference
In a biprism experiment, the distance of 20 th bright bandfrom the center of the interference pattern is 8mm . The distance of 30th bright band from the center is
  • 11.8mm
  • 12mm
  • 14mm
  • 16mm
If the ratio of maximum and maximum Intensities tn an interference pattern is 36: 1 then the ratio of amplitudes of two Interfering waves Will be
  • 5 :7
  • 7 :4
  • 4 :7
  • 7 :5
In Y.D.S.E. how many maxima can be obtained on the screen if wave length of light used is 200mm & d=700mm :- 
  • 12
  • 7
  • 18
  • 14
What is the effect on the interference fringes in Young's double slit experiment if the source slit is moved closer to the double slit plane?
  • The fringe width increases
  • The fringe width decreases
  • The fringes become more distinct
  • The fringes become less distinct
If the frequency of the source is doubled in Young's double slit experiment, then fringe width (β) will be-
  • unchanged
  • β/2
  • 2β
  • 3β
In YDSE if white is used then.
  • except center, there will be spectrum
  • except center no spectrum any where
  • spectrum every where
  • spectrum at center only
In a double-slit experiment, green light (5303oA) falls on a double slit having a separation of 19.44 μm and a width of 4.05 μm. The number of bright fringes between the first and the second diffraction minima is?
  • 09
  • 10
  • 04
  • 05
When an unpolarized light of intensity I0 is incident on a polarizing sheet the intensity of the light which does not get transmitted is?
  • Zero
  • I0
  • 12I0
  • None
Huygen's theory of secondary waves can be used of find-
  • Velocity of light
  • The wavelength of light
  • Wave front geometrically
  • Magnifying power of microscope
The wavefront of a light beam is given by the equation x+2y+3z=c , (where c is arbitrary constant) then what is the angle made by the direction of light with the y-axis?
  • cos2214
  • cos1214
  • cos3214
  • cos4214
Consider Fraunhoffer diffraction pattern obtained with a single slit illuminate incidance. At the angular position of the first diffraction minimum in the phase( radian) between the wavelets from the opposite edges of the slit is  
  • π4
  • π2
  • π
  • 2π
What wavelength of light would you be able to resolve at the fastest distance based on diffraction?
  • Red (λ=650nm)
  • Green (λ=550nm)
  • Blue (λ=450nm)
  • All the wavelengths will be resolved equally
Fraunhoffer lines are obtained in
  • Solar spectrum
  • The spectrum obtained from neon lamp
  • Spectrum from a discharge tube
  • None of the above
The figure shows a double slit experiment where P and Q are the slits. The path lengths PX and QX are nλ and (n+2)λ respectively, where n is a whole number and λ is the wavelength. Taking the central fringe as zero, what is formed at X
1378273_676d3d1faedd47759fd9fb6ace92480c.png
  • First bright
  • First dark
  • Second bright
  • Second dark
Which of following nature of light waves is supported by the phenomenon of interference:
  • longitudinal
  • transverse
  • both transverse and longitudinal
  • none of the above
Light of wavelength 6000 is incident bria single slit. The first minimum of the diffraction pattern is obtained at 4 mm from the centre. The screen is at a distance of 2 m from the slit.
  • 0.15 mm
  • 0.1 mm
  • 0.3 mm
  • 0.2 mm
We could observe path of light due to ........... of light from tiny particle of solution of transparent medium.
  • Scatterign
  • Dispersion
  • Refraction
  • Reflaction
Electrons accelerated by potential V are diffracted from a crystal. If d=1A and i=30,V should be about (h=6.6×1034Js,me=9.1×1031kg,e=1.6×1019C).
  • 2000 V
  • 50 V
  • 500 V
  • 1000 V
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 12 Medical Physics Quiz Questions and Answers