JEE Main & Advanced Physics Wave Optics / तरंग प्रकाशिकी Question Bank

done Young's Double Slit Experiment and Biprism Total Questions - 97

• question_answer1)
  Young's experiment establishes that [CPMT 1972; MP PET 1994, 98; MP PMT 1998]
  A)
             Light consists of waves     done clear
  B)
             Light consists of particles done clear
  C)
             Light consists of neither particles nor waves done clear
  D)
             Light consists of both particles and waves done clear
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• question_answer2)
  In the interference pattern, energy is
  A)
             Created at the position of maxima done clear
  B)
             Destroyed at the position of minima done clear
  C)
             Conserved but is redistributed done clear
  D)
             None of the above done clear
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• question_answer3)
  Monochromatic green light of wavelength \[5\times {{10}^{-7}}m\]illuminates a pair of slits 1 mm apart. The separation of bright lines on the interference pattern formed on a screen 2 m away is                                [CPMT 1971; DPMT 1999]
  A)
             0.25 mm                                  done clear
  B)
             0.1 mm done clear
  C)
             1.0 mm                                    done clear
  D)
             0.01 mm done clear
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• question_answer4)
  In Young's double slit experiment, if the slit widths are in the ratio 1 : 9, then the ratio of the intensity at minima to that at maxima will be                                                             [MP PET 1987]
  A)
             1     done clear
  B)
             1/9 done clear
  C)
             1/4 done clear
  D)
             1/3 done clear
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• question_answer5)
  In Young's double slit interference experiment, the slit separation is made 3 fold. The fringe width becomes [CPMT 1982, 89]
  A)
             1/3 times                                done clear
  B)
             1/9 times done clear
  C)
             3 times                                     done clear
  D)
             9 times done clear
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• question_answer6)
  In a certain double slit experimental arrangement interference fringes of width 1.0 mm each are observed when light of wavelength 5000 Å is used. Keeping the set up unaltered, if the source is replaced by another source of wavelength 6000 Å, the fringe width will be                [CPMT 1988]
  A)
             0.5 mm                                    done clear
  B)
             1.0 mm done clear
  C)
             1.2 mm                                    done clear
  D)
             1.5 mm done clear
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• question_answer7)
  Two coherent light sources S1 and S2 (l= 6000 Å) are 1mm apart from each other. The screen is placed at a distance of 25 cm from the sources. The width of the fringes on the screen should be                                        [CPMT 1990]
  A)
             0.015 cm                                 done clear
  B)
             0.025 cm done clear
  C)
             0.010 cm                                 done clear
  D)
             0.030 cm done clear
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• question_answer8)
  The figure shows a double slit experiment P and Q are the slits. The path lengths PX and QX are \[n\lambda \]  and \[(n+2)\lambda \] respectively, where n is a whole number and l is the wavelength. Taking the central fringe as zero, what is formed at X
  A)
             First bright done clear
  B)
             First dark done clear
  C)
             Second bright done clear
  D)
             Second dark done clear
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• question_answer9)
  In Young's double slit experiment, if one of the slit is closed fully, then in the interference pattern
  A)
             A bright slit will be observed, no interference pattern will exist done clear
  B)
             The bright fringes will become brighter done clear
  C)
             The bright fringes will become fainter done clear
  D)
             None of the above done clear
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• question_answer10)
  In Young's double slit experiment, a glass plate is placed before a slit which absorbs half the intensity of light. Under this case
  A)
             The brightness of fringes decreases done clear
  B)
             The fringe width decreases done clear
  C)
             No fringes will be observed done clear
  D)
             The bright fringes become fainter and the dark fringes have finite light intensity done clear
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• question_answer11)
  In Young's experiment, the distance between the slits is reduced to half and the distance between the slit and screen is doubled, then the fringe width [IIT 1981; MP PMT 1994; RPMT 1997; KCET 2000;  CPMT 2003; AMU (Engg.) 2000; DPMT 2003; UPSEAT 2000, 04; Kerala PMT 2004]
  A)
             Will not change                    done clear
  B)
             Will become half done clear
  C)
             Will be doubled                   done clear
  D)
             Will become four times done clear
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• question_answer12)
  The maximum intensity of fringes in Young's experiment is I. If one of the slit is closed, then the intensity at that place becomes Io. Which of the following relation is true? [NCERT 1982; MP PMT 1994, 99; BHU 1998; RPMT 1996; RPET 1999; AMU (Engg.) 1999]
  A)
             I = Io done clear
  B)
             I = 2Io done clear
  C)
             I = 4Io                                                            done clear
  D)
             There is no relation between I and Io done clear
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• question_answer13)
  In the Young's double slit experiment, the ratio of intensities of bright and dark fringes is 9. This means that [IIT 1982]
  A)
             The intensities of individual sources are 5 and 4 units respectively done clear
  B)
             The intensities of individual sources are 4 and 1 units respectively done clear
  C)
             The ratio of their amplitudes is 3 done clear
  D)
             The ratio of their amplitudes is 2 done clear
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• question_answer14)
  An oil flowing on water seems coloured due to interference. For observing this effect, the approximate thickness of the oil film should be                                  [DPET 1987; JIPMER 1997; RPMT 2002, 04]
  A)
  \[100\,\,{AA}\] done clear
  B)
  \[10000\,\,{AA}\] done clear
  C)
  1 mm done clear
  D)
  1 cm done clear
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• question_answer15)
  The Young's experiment is performed with the lights of blue (l = 4360 Å) and green colour (l = 5460 Å), If the distance of the 4th fringe from the centre is x, then             [CPMT 1987]
  A)
             x (Blue) = x (Green)           done clear
  B)
             x (Blue)> x (Green) done clear
  C)
             x (Blue) < x (Green)           done clear
  D)
             \[\frac{x(Blue)}{x(Green)}=\frac{5460}{4360}\] done clear
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• question_answer16)
  In the Young's double slit experiment, the spacing between two slits is 0.1 mm. If the screen is kept at a distance of 1.0 m from the slits and the wavelength of light is 5000 Å, then the fringe width is         [MP PMT 1993; RPET 1996]
  A)
             1.0 cm                                      done clear
  B)
             1.5 cm done clear
  C)
             0.5 cm                                      done clear
  D)
             2.0 cm done clear
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• question_answer17)
  In Young's double slit experiment, if L is the distance between the slits and the screen upon which interference pattern is observed, x is the average distance between the adjacent fringes and d being the slit separation. The wavelength of light is given by                                                     [MP PET 1993]
  A)
             \[\frac{xd}{L}\]                    done clear
  B)
             \[\frac{xL}{d}\] done clear
  C)
             \[\frac{Ld}{x}\]                    done clear
  D)
             \[\frac{1}{Ldx}\] done clear
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• question_answer18)
  In a Young's double slit experiment, the central point on the screen is                                    [MP PMT 1996]
  A)
             Bright                                       done clear
  B)
             Dark done clear
  C)
             First bright and then dark        done clear
  D)
             First dark and then bright done clear
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• question_answer19)
  In a 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 [CBSE PMT 1990]
  A)
             0.30 mm                                  done clear
  B)
             0.40 mm done clear
  C)
             0.53 mm                                  done clear
  D)
             450 micron done clear
  View Solution play_arrow

• question_answer20)
  Young's experiment is performed in air and then performed in water, the fringe width  [CPMT 1990; MP PMT 1994; RPMT 1997; Kerala PMT 2004]
  A)
             Will remain same                done clear
  B)
             Will decrease done clear
  C)
             Will increase                          done clear
  D)
             Will be infinite done clear
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• question_answer21)
  In double slits experiment, for light of which colour the fringe width will be minimum                     [MP PMT 1994]
  A)
             Violet                                       done clear
  B)
             Red done clear
  C)
             Green                                      done clear
  D)
             Yellow done clear
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• question_answer22)
  In Young's experiment, light of wavelength 4000 Å is used to produce bright fringes of width 0.6 mm, at a distance of 2 meters. If the whole apparatus is dipped in a liquid of refractive index 1.5, then fringe width will be         [MP PMT 1994]
  A)
             0.2 mm done clear
  B)
             0.3 mm done clear
  C)
             0.4 mm                                    done clear
  D)
             1.2 mm done clear
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• question_answer23)
  In Young's double slit experiment, the phase difference between the light waves reaching third bright fringe from the central fringe will be (l =6000 Å )                       [MP PMT 1994]
  A)
             Zero                                          done clear
  B)
             \[2\pi \] done clear
  C)
             \[4\pi \]                                   done clear
  D)
             \[6\pi \] done clear
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• question_answer24)
  In Young's double slit experiment, if the widths of the slits are in the ratio 4 : 9, the ratio of the intensity at maxima to the intensity at minima will be                             [Manipal MEE 1995]
  A)
             169 : 25                                    done clear
  B)
             81 : 16 done clear
  C)
             25 : 1                                         done clear
  D)
             9 : 4 done clear
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• question_answer25)
  In Young's double slit experiment when wavelength used is 6000 Å and the screen is 40 cm from the slits, the fringes are 0.012 cm wide. What is the distance between the slits [MP PMT 1995; Pb PET 2002]
  A)
             0.024 cm                                 done clear
  B)
             2.4 cm done clear
  C)
             0.24 cm                                    done clear
  D)
             0.2 cm done clear
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• question_answer26)
  In two separate set - ups of the Young's double slit experiment, fringes of equal width are observed when lights of wavelengths in the ratio 1 : 2 are used. If the ratio of the slit separation in the two cases is 2 : 1, the ratio of the distances between the plane of the slits and the screen in the two set - ups is                                        [KCET 1996]
  A)
             4 : 1                                           done clear
  B)
             1 : 1 done clear
  C)
             1 : 4                                           done clear
  D)
             2 : 1 done clear
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• question_answer27)
  In an interference experiment, the spacing between successive maxima or minima is                     [MP PET 1996]
  A)
             \[\frac{\lambda d}{D}\]    done clear
  B)
             \[\frac{\lambda D}{d}\] done clear
  C)
             \[\frac{dD}{\lambda }\]    done clear
  D)
             \[\frac{\lambda d}{4D}\] (Where the symbols have their usual meanings) done clear
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• question_answer28)
  If yellow light in the Young's double slit experiment is replaced by red light, the fringe width will                [MP PMT 1996]
  A)
             Decrease done clear
  B)
             Remain unaffected done clear
  C)
             Increase                                  done clear
  D)
             First increase and then decrease done clear
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• question_answer29)
  In Young's double slit experiment, the fringe width is \[1\times {{10}^{-4}}m\]if the distance between the slit and screen is doubled and the distance between the two slit is reduced to half and wavelength is changed from \[6.4\times {{10}^{7}}m\] to \[4.0\times {{10}^{-7}}m\], the value of new fringe width will be
  A)
             \[0.15\times {{10}^{-4}}m\]   done clear
  B)
             \[2.0\times {{10}^{-4}}m\] done clear
  C)
             \[1.25\times {{10}^{-4}}m\]   done clear
  D)
             \[2.5\times {{10}^{-4}}m\] done clear
  View Solution play_arrow

• question_answer30)
  In Young's experiment, one slit is covered with a blue filter and the other (slit) with a yellow filter. Then the interference pattern                                                       [MP PET 1997]
  A)
             Will be blue                           done clear
  B)
             Will be yellow done clear
  C)
             Will be green                        done clear
  D)
             Will not be formed done clear
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• question_answer31)
  Two sources give interference pattern which is observed on a screen, D distance apart from the sources. The fringe width is 2w. If the distance D is now doubled, the fringe width will                                        [MP PET 1997]
  A)
             Become w/2                         done clear
  B)
             Remain the same done clear
  C)
             Become w                              done clear
  D)
             Become 4w done clear
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• question_answer32)
  In double slit experiment, the angular width of the fringes is 0.20o for the sodium light (l =\[5890\,{AA}\]). In order to increase the angular width of the fringes by 10%, the necessary change in the wavelength is                 [MP PMT 1997]
  A)
  Increase of\[589\,\,{AA}\]    done clear
  B)
  Decrease of\[589\,\,{AA}\] done clear
  C)
  Increase of\[6479\,\,{AA}\] done clear
  D)
  Zero done clear
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• question_answer33)
  In a biprism experiment, by using light of wavelength 5000 Å, 5 mm wide fringes are obtained on a screen 1.0 m away from the coherent sources. The separation between the two coherent sources is                       [MP PMT/PET 1998]
  A)
             1.0 mm                                    done clear
  B)
             0.1 mm done clear
  C)
             0.05 mm                                  done clear
  D)
             0.01 mm done clear
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• question_answer34)
  The slits in a Young's double slit experiment have equal widths and the source is placed symmetrically relative to the slits. The intensity at the central fringes is I0. If one of the slits is closed, the intensity at this point will be                    [MP PMT 1999; Orissa JEE 2004; Kerala PET 2005]
  A)
             I0     done clear
  B)
             I0 / 4 done clear
  C)
             I0 / 2                                          done clear
  D)
             4I0 done clear
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• question_answer35)
  A thin mica sheet of thickness \[2\times {{10}^{-6}}m\]and refractive index \[(\mu =1.5)\] is introduced in the path of the first wave. The wavelength of the wave used is 5000 Å. The central bright maximum will shift                                     [CPMT 1999]
  A)
             2 fringes upward                 done clear
  B)
             2 fringes downward done clear
  C)
             10 fringes upward               done clear
  D)
             None of these done clear
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• question_answer36)
  In a Young's double slit experiment, the fringe width will remain same, if (D = distance between screen and plane of slits, d = separation between two slits and l =  wavelength of light used)                                            [Bihar MEE 1995]
  A)
             Both l and\[D\]are doubled done clear
  B)
             Both d and\[D\]are doubled done clear
  C)
             D is doubled but d is halved done clear
  D)
             l is doubled but d is halved done clear
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• question_answer37)
  In Young's double slit experiment, the slits are 0.5 mm apart and interference pattern is observed on a screen placed at a distance of 1.0 m from the plane containing the slits. If wavelength of the incident light is 6000 Å, then the separation between the third bright fringe and the central maxima is                                            [AMU 1995]
  A)
             4.0 mm                                    done clear
  B)
             3.5 mm done clear
  C)
             3.0 mm                                    done clear
  D)
             2.5 mm done clear
  View Solution play_arrow

• question_answer38)
  In Young's double slit experiment, 62 fringes are seen in visible region for sodium light of wavelength 5893 Å. If violet light of wavelength 4358 Å is used in place of sodium light, then number of fringes seen will be           [RPET 1997]
  A)
             54   done clear
  B)
             64 done clear
  C)
             74   done clear
  D)
             84 done clear
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• question_answer39)
  In Young's double slit experiment, angular width of fringes is 0.20o for sodium light of wavelength 5890 Å. If complete system is dipped in water, then angular width of fringes becomes                                            [RPET 1997]
  A)
             0.11o                                                              done clear
  B)
             0.15o done clear
  C)
             0.22o                                                              done clear
  D)
             0.30o done clear
  View Solution play_arrow

• question_answer40)
  In Young's double slit experiment, the distance between the slits is 1 mm and that between slit and screen is 1 meter and 10th fringe is 5 mm away from the central bright fringe, then wavelength of light used will be     [RPMT 1997]
  A)
  \[5000\,\,{AA}\]                done clear
  B)
  \[6000\,\,{AA}\] done clear
  C)
  \[7000\,\,{AA}\]                done clear
  D)
  \[8000\,\,{AA}\] done clear
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• question_answer41)
  In Young's double slit experiment, carried out with light of wavelength l = 5000 Å, the distance between the slits is 0.2 mm and the screen is at 200 cm from the slits. The central maximum is at x =0. The third maximum (taking the central maximum as zeroth maximum) will be at x equal to [CBSE PMT 1992; MH CET 2002]
  A)
             1.67 cm                                    done clear
  B)
             1.5 cm done clear
  C)
             0.5 cm                                      done clear
  D)
             5.0 cm done clear
  View Solution play_arrow

• question_answer42)
  In a Young's experiment, two coherent sources are placed 0.90 mm apart and the fringes are observed one metre away. If it produces the second dark fringe at a distance of 1 mm from the central fringe, the wavelength of monochromatic light used would be [CBSE PMT 1992; KCET 2004]
  A)
             \[60\times {{10}^{-4}}cm\]     done clear
  B)
             \[10\times {{10}^{-4}}cm\] done clear
  C)
             \[10\times {{10}^{-5}}cm\]     done clear
  D)
             \[6\times {{10}^{-5}}cm\] done clear
  View Solution play_arrow

• question_answer43)
  In Young's double slit experiment, the distance between the two slits is 0.1 mm and the wavelength of light used is \[4\times {{10}^{-7}}m\]. If the width of the fringe on the screen is 4 mm, the distance between screen and slit is [Bihar CMEET 1995]
  A)
             0.1 mm                                    done clear
  B)
             1 cm done clear
  C)
             0.1 cm                                      done clear
  D)
             1 m done clear
  View Solution play_arrow

• question_answer44)
  In Young's double slit experiment, the distance between sources is 1 mm and distance between the screen and source is 1 m. If the fringe width on the screen is 0.06 cm, then l =                                [CPMT 1996]
  A)
  \[6000\,\,{AA}\] done clear
  B)
  \[4000\,\,{AA}\] done clear
  C)
  \[1200\,\,{AA}\] done clear
  D)
  \[2400\,\,{AA}\] done clear
  View Solution play_arrow

• question_answer45)
  In Young's double slit experiment, a mica slit of thickness t and refractive index m is introduced in the ray from the first source S1. By how much distance the fringes pattern will be displaced    [RPMT 1996, 97; JIPMER 2000; RPMT 2003]
  A)
             \[\frac{d}{D}(\mu -1)\ t\]        done clear
  B)
             \[\frac{D}{d}(\mu -1)\ t\] done clear
  C)
             \[\frac{d}{(\mu -1)D}\]     done clear
  D)
             \[\frac{D}{d}(\mu -1)\] done clear
  View Solution play_arrow

• question_answer46)
  In Young's double slit experiment using sodium light\[(l=5898\,\,{AA})\], 92 fringes are seen. If given colour\[(l=5461\,\,{AA})\]is used, how many fringes will be seen  [CPMT 1989; RPET 1996; JIPMER 2001, 02]
  A)
  62   done clear
  B)
  67 done clear
  C)
  85   done clear
  D)
  99 done clear
  View Solution play_arrow

• question_answer47)
  If a torch is used in place of monochromatic light in Young?s experiment what will happens [MH CET 1999; KCET 1999]
  A)
             Fringe will appear for a moment then it will disappear done clear
  B)
             Fringes will occur as from monochromatic light done clear
  C)
             Only bright fringes will appear done clear
  D)
             No fringes will appear done clear
  View Solution play_arrow

• question_answer48)
  When a thin metal plate is placed in the path of one of the interfering beams of light                      [KCET 1999]
  A)
             Fringe width increases     done clear
  B)
             Fringes disappear done clear
  C)
             Fringes become brighter         done clear
  D)
             Fringes becomes blurred done clear
  View Solution play_arrow

• question_answer49)
  In Young's experiment, the distance between slits is 0.28 mm and distance between slits and screen is 1.4 m. Distance between central bright fringe and third bright fringe is 0.9 cm. What is the wavelength of used light            [KCET 1999]
  A)
  \[5000\,\,{AA}\] done clear
  B)
  \[6000\,\,{AA}\] done clear
  C)
  \[7000\,\,{AA}\] done clear
  D)
  \[9000\,\,{AA}\] done clear
  View Solution play_arrow

• question_answer50)
  Two parallel slits 0.6 mm apart are illuminated by light source of wavelength 6000 Å. The distance between two consecutive dark fringes on a screen 1 m away from the slits is                                                            [JIPMER 1999]
  A)
             1 mm                                        done clear
  B)
             0.01 mm  done clear
  C)
             0.1 m                                        done clear
  D)
             10 m done clear
  View Solution play_arrow

• question_answer51)
  In young?s double slit experiment with a source of light of wavelength\[6320\,\,{AA}\], the first maxima will occur when [Roorkee 1999]
  A)
  Path difference is\[9480\,\,{AA}\] done clear
  B)
  Phase difference is 2p radian done clear
  C)
  Path difference is\[6320\,\,{AA}\] done clear
  D)
  Phase difference is p radian done clear
  View Solution play_arrow

• question_answer52)
  If a transparent medium of refractive index m = 1.5 and thickness t = 2.5 ´ 10?5 m is inserted in front of one of the slits of Young?s Double Slit experiment, how much will be the shift in the interference pattern? The distance between the slits is 0.5 mm and that between slits and screen is 100 cm                                                        [AIIMS 1999]
  A)
             5 cm                                          done clear
  B)
             2.5 cm done clear
  C)
             0.25 cm                                    done clear
  D)
             0.1 cm done clear
  View Solution play_arrow

• question_answer53)
  In Young?s experiment, monochromatic light is used to illuminate the two slits A and B. Interference fringes are observed on a screen placed in front of the slits. Now if a thin glass plate is placed normally in the path of the beam coming from the slit [UPSEAT 1993, 2000; AIIMS 1999, 2004]
  A)
             The fringes will disappear done clear
  B)
             The fringe width will increase done clear
  C)
             The fringe width will increase done clear
  D)
             There will be no change in the fringe width but the pattern shifts done clear
  View Solution play_arrow

• question_answer54)
  The fringe width in Young?s double slit experiment increases when                                         [MP PMT 2000]
  A)
             Wavelength increases done clear
  B)
             Distance between the slits increases done clear
  C)
             Distance between the source and screen decreases done clear
  D)
             The width of the slits increases done clear
  View Solution play_arrow

• question_answer55)
  In a double slit experiment, instead of taking slits of equal widths, one slit is made twice as wide as the other. Then in the interference pattern                           [IIT-JEE (Screening) 2000]
  A)
             The intensities of both the maxima and the minima increase  done clear
  B)
             The intensity of maxima increases and the minima has zero intensity done clear
  C)
             The intensity of maxima decreases and that of the minima increases done clear
  D)
             The intensity of maxima decreases and the minima has zero intensity done clear
  View Solution play_arrow

• question_answer56)
  Two slits, 4 mm apart, are illuminated by light of wavelength 6000 Å. What will be the fringe width on a screen placed 2m from the slits                                                                [MP PET 2000]
  A)
             0.12 mm                                  done clear
  B)
             0.3 mm done clear
  C)
             3.0 mm                                    done clear
  D)
             4.0 mm done clear
  View Solution play_arrow

• question_answer57)
  In the Young?s double slit experiment, for which colour the fringe width is least                 [UPSEAT 2001, MP PET 2001]
  A)
             Red                                           done clear
  B)
             Green done clear
  C)
             Blue                                          done clear
  D)
             Yellow done clear
  View Solution play_arrow

• question_answer58)
  In a Young?s double slit experiment, the separation of the two slits is doubled. To keep the same spacing of fringes, the distance D of the screen from the slits should be made  [MNR 1998; AMU (Engg.) 2001]
  A)
             \[\frac{D}{2}\]                      done clear
  B)
             \[\frac{D}{\sqrt{2}}\] done clear
  C)
             2D done clear
  D)
             4D done clear
  View Solution play_arrow

• question_answer59)
  Young?s double slit experiment is performed with light of wavelength 550 nm. The separation between the slits is 1.10 mm and screen is placed at distance of 1 m. What is the distance between the consecutive bright or dark fringes [Pb. PMT 2000]
  A)
             1.5 mm                                    done clear
  B)
             1.0 mm done clear
  C)
             0.5 mm                                    done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer60)
  In Young?s experiment, the ratio of maximum to minimum intensities of the fringe system is 4 : 1. The amplitudes of the coherent sources are in the ratio   [RPMT 1996; MP PET 2000; RPET 2001; MP PMT 2001]
  A)
             4 : 1                                           done clear
  B)
             3 : 1 done clear
  C)
             2 : 1                                           done clear
  D)
             1 : 1 done clear
  View Solution play_arrow

• question_answer61)
  An interference pattern was made by using red light. If the red light changes with blue light, the fringes will become [BHU 2001]
  A)
             Wider                                       done clear
  B)
             Narrower done clear
  C)
             Fainter                                     done clear
  D)
             Brighter done clear
  View Solution play_arrow

• question_answer62)
   If a white light is used in Young?s double slit experiments then a very large number of coloured fringes can be seen  [KCET 2001]
  A)
             With first order violet fringes being closer to the central white fringes done clear
  B)
             First order red fringes being closer to the central white fringes done clear
  C)
             With a central white fringe done clear
  D)
             With a central black fringe done clear
  View Solution play_arrow

• question_answer63)
  In a Young?s double slit experiment, 12 fringes are observed to be formed in a certain segment of the screen when light of wavelength 600 nm is used. If the wavelength of light is changed to 400 nm, number of fringes observed in the same segment of the screen is given by       [IIT-JEE (Screening) 2001]
  A)
             12   done clear
  B)
             18 done clear
  C)
             24   done clear
  D)
             30 done clear
  View Solution play_arrow

• question_answer64)
  In the Young?s double slit experiment with sodium light. The slits are 0.589 m a part. The angular separation of the third maximum from  the central maximum will be (given l = 589 mm)                                              [Pb. PMT 2002]
  A)
             \[{{\sin }^{-1}}(0.33\times {{10}^{8}})\]                        done clear
  B)
             \[{{\sin }^{-1}}(0.33\times {{10}^{-6}})\] done clear
  C)
             \[{{\sin }^{-1}}(3\times {{10}^{-8}})\]                             done clear
  D)
             \[{{\sin }^{-1}}(3\times {{10}^{-6}})\] done clear
  View Solution play_arrow

• question_answer65)
  In Young?s double slit experiment, the distance between the two slits is made half, then the fringe width will become [RPMT 1999; BHU 2002]
  A)
             Half                                           done clear
  B)
             Double done clear
  C)
             One fourth                            done clear
  D)
             Unchanged done clear
  View Solution play_arrow

• question_answer66)
  In Young?s double slit experiment, the central bright fringe can be identified                                       [KCET 2002]
  A)
             By using white light instead of monochromatic light done clear
  B)
             As it is narrower than other bright fringes done clear
  C)
             As it is wider than other bright fringes done clear
  D)
             As it has a greater intensity than the other bright fringes done clear
  View Solution play_arrow

• question_answer67)
  In Young?s double slit experiment, the wavelength of the light used is doubled and distance between two slits is half of initial distance, the resultant fringe width becomes   [AIEEE 2002]
  A)
             2 times                                     done clear
  B)
             3 times done clear
  C)
             4 times                                     done clear
  D)
             1/2 times done clear
  View Solution play_arrow

• question_answer68)
  In a Young?s double slit experiment, the source illuminating the slits is changed from blue to violet. The width of the fringes                                                                       [KCET 2002]
  A)
             Increases                                done clear
  B)
             Decreases done clear
  C)
             Becomes unequal               done clear
  D)
             Remains constant done clear
  View Solution play_arrow

• question_answer69)
  In Young?s double slit experiment, the intensity of light coming from the first slit is double the intensity from the second slit. The ratio of the maximum intensity to the minimum intensity on the interference fringe pattern observed is                                                                            [KCET 2002]
  A)
             34   done clear
  B)
             40 done clear
  C)
             25   done clear
  D)
             38 done clear
  View Solution play_arrow

• question_answer70)
  If the sodium light in Young?s double slit experiment is replaced by red light, the fringe width will              [MP PMT 2002]
  A)
             Decrease done clear
  B)
             Increase  done clear
  C)
             Remain unaffected done clear
  D)
             First increase, then decrease done clear
  View Solution play_arrow

• question_answer71)
  In Young?s double slit experiment the wavelength of light was changed from 7000 Å to 3500 Å. While doubling the separation between the slits which of the following is not true for this experiment                                          [Orissa JEE 2002]
  A)
             The width of the fringes changes done clear
  B)
             The colour of bright fringes changes done clear
  C)
             The separation between successive bright fringes changes done clear
  D)
             The separation between successive dark fringes remains unchanged done clear
  View Solution play_arrow

• question_answer72)
  When a thin transparent plate of thickness t and refractive index m is placed in the path of one of the two interfering waves of light, then the path difference changes by  [MP PMT 2002]
  A)
             (m + 1)t                                    done clear
  B)
             (m ? 1)t done clear
  C)
             \[\frac{(\mu +1)}{t}\]        done clear
  D)
             \[\frac{(\mu -1)}{t}\] done clear
  View Solution play_arrow

• question_answer73)
  In Young's double-slit experiment, an interference pattern is obtained on a screen by a light of wavelength\[6000\,\,{AA}\], coming from the coherent sources S1 and S2. At certain point P on the screen third dark fringe is formed. Then the path difference S1P ? S2P in microns is              [EAMCET 2003]
  A)
  0.75                                           done clear
  B)
  1.5 done clear
  C)
  3.0  done clear
  D)
  4.5 done clear
  View Solution play_arrow

• question_answer74)
  In a Young?s double slit experiment, the slit separation is 1 mm and the screen is 1 m from the slit. For a monochromatic light of wavelength 500 nm, the distance of 3rd minima from the central maxima is          [Orissa JEE 2003]
  A)
             0.50 mm                                  done clear
  B)
             1.25 mm done clear
  C)
             1.50 mm                                  done clear
  D)
             1.75 mm done clear
  View Solution play_arrow

• question_answer75)
  In Young?s double-slit experiment the fringe width is b. If entire arrangement is placed in a liquid of refractive index n, the fringe width becomes                                                   [KCET 2003]
  A)
             \[\frac{\beta }{n+1}\]       done clear
  B)
             nb done clear
  C)
             \[\frac{\beta }{n}\]            done clear
  D)
             \[\frac{\beta }{n-1}\] done clear
  View Solution play_arrow

• question_answer76)
  In an interference experiment, third bright fringe is obtained at a point on the screen with a light of 700 nm. What should be the wavelength of the light source in order to obtain 5th bright fringe at the same point         [KCET 2003]
  A)
             500 nm done clear
  B)
             630 nm  done clear
  C)
             750 nm done clear
  D)
             420 nm done clear
  View Solution play_arrow

• question_answer77)
  If the separation between slits in Young?s double slit experiment is reduced to \[\frac{1}{3}rd,\] the fringe width becomes n times. The value of n is                                         [MP PET 2003]
  A)
             3     done clear
  B)
             \[\frac{1}{3}\] done clear
  C)
             9     done clear
  D)
             \[\frac{1}{9}\] done clear
  View Solution play_arrow

• question_answer78)
  A double slit experiment is performed with light of wavelength 500 nm. A thin film of thickness 2 mm and refractive index 1.5 is introduced in the path of the upper beam. The location of the central maximum will [AIIMS 2003]
  A)
             Remain unshifted done clear
  B)
             Shift downward by nearly two fringes done clear
  C)
             Shift upward by nearly two fringes done clear
  D)
             Shift downward by 10 fringes done clear
  View Solution play_arrow

• question_answer79)
  The two slits at a distance of 1 mm are illuminated by the light of wavelength \[6.5\times {{10}^{-7}}m\]. The interference fringes  are observed on a screen placed at a distance of 1m. The distance between third dark fringe and fifth bright fringe will be      [NCERT 1982; MP PET 1995; BVP 2003]
  A)
             0.65 mm done clear
  B)
             1.63 mm done clear
  C)
             3.25 mm                                  done clear
  D)
             4.88 mm done clear
  View Solution play_arrow

• question_answer80)
  In a Young?s double-slit experiment the fringe width is 0.2 mm. If the wavelength of light used is increased by 10% and the separation between the slits is also increased by 10%, the fringe width will be                    [MP PMT 2004]
  A)
             0.20 mm done clear
  B)
             0.401 mm done clear
  C)
             0.242 mm                               done clear
  D)
              0.165 mm done clear
  View Solution play_arrow

• question_answer81)
  Two coherent sources of intensity ratio 1 : 4 produce an interference pattern. The fringe visibility will be [J & K CET 2004]
  A)
             1     done clear
  B)
             0.8 done clear
  C)
             0.4  done clear
  D)
              0.6 done clear
  View Solution play_arrow

• question_answer82)
  In Young?s double slit experiment the amplitudes of two sources are 3a and a respectively. The ratio of intensities of bright and dark fringes will be                       [J & K CET 2004]
  A)
             3 : 1                                           done clear
  B)
             4 : 1 done clear
  C)
             2 : 1                                           done clear
  D)
              9 : 1 done clear
  View Solution play_arrow

• question_answer83)
  In Young?s double slit experiment, distance between two sources is 0.1 mm. The distance of screen from the sources is 20 cm. Wavelength of light used is 5460 Å. Then angular position of the first dark fringe is  [DCE 2002]
  A)
             0.08°                                         done clear
  B)
             0.16° done clear
  C)
             0.20°                                         done clear
  D)
             0.313° done clear
  View Solution play_arrow

• question_answer84)
  In a Young?s double slit experiment, the slit separation is 0.2 cm, the distance between the screen and slit is 1m. Wavelength of the light used is 5000 Å. The distance between two consecutive dark fringes (in mm) is [DCE 2004]
  A)
             0.25                                           done clear
  B)
             0.26 done clear
  C)
             0.27                                           done clear
  D)
              0.28 done clear
  View Solution play_arrow

• question_answer85)
  A light of wavelength\[5890\,\,{AA}\]falls normally on a thin air film. The minimum thickness of the film such that the film appears dark in reflected light                             [Pb. PMT 2003]
  A)
  \[2.945\times {{10}^{-7}}m\]                                             done clear
  B)
  \[3.945\times {{10}^{-7}}m\] done clear
  C)
  \[4.95\times {{10}^{-7}}m\]   done clear
  D)
  \[1.945\times {{10}^{-7}}m\] done clear
  View Solution play_arrow

• question_answer86)
  In Young?s double slit experiment, a minimum is obtained when the phase difference of super imposing waves is [MH CET 2004]
  A)
             Zero                                          done clear
  B)
             \[(2n-1)\,\,\pi \] done clear
  C)
             \[n\pi \]                                  done clear
  D)
              \[(n+1)\,\,\pi \] done clear
  View Solution play_arrow

• question_answer87)
  In Fresnel's biprism \[(\mu =1.5)\] experiment the distance between source and biprism is 0.3 m and that between biprism and screen is 0.7m and angle of prism is \[1{}^\circ \]. The fringe width with light of wavelength\[6000\,\,{AA}\]will be [RPMT 2002]
  A)
  3 cm                                         done clear
  B)
  0.011 cm done clear
  C)
  2 cm                                          done clear
  D)
  4 cm done clear
  View Solution play_arrow

• question_answer88)
  In Young double slit experiment, when two light waves form third minimum, they have                [RPMT 2003]
  A)
             Phase difference of \[3\pi \]                                             done clear
  B)
             Phase difference of \[\frac{5\pi }{2}\] done clear
  C)
             Path difference of \[3\lambda \]                                     done clear
  D)
             Path difference of \[\frac{5\lambda }{2}\] done clear
  View Solution play_arrow

• question_answer89)
  In Fresnel?s biprism experiment, on increasing the prism angle, fringe width will                                                [RPMT 2003]
  A)
             Increase done clear
  B)
             Decrease                                done clear
  C)
             Remain unchanged            done clear
  D)
              Depend on the position of object done clear
  View Solution play_arrow

• question_answer90)
  If prism angle \[\alpha =1{}^\circ ,\ \mu =1.54,\]distance between screen and prism \[(b)=0.7\,m,\] distance between prism and source \[a=0.3\,m,\ \lambda =180\pi \ nm\] then in Fresnal biprism find the value of \[\beta \] (fringe width)                                                                       [RPMT 2002]
  A)
             \[{{10}^{-4}}m\]                  done clear
  B)
             \[{{10}^{-3}}mm\] done clear
  C)
             \[{{10}^{-4}}\times \pi m\]     done clear
  D)
              \[\pi \times {{10}^{-3}}m\] done clear
  View Solution play_arrow

• question_answer91)
  If Fresnel?s biprism experiment as held in water inspite of air, then what will be the effect on fringe width [RPMT 1997, 98]
  A)
             Decrease done clear
  B)
             Increase done clear
  C)
             No effect done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer92)
  What is the effect on Fresnel?s biprism experiment when the use of white light is made                [RPMT 1998]
  A)
             Fringe are affected done clear
  B)
             Diffraction pattern is spread more done clear
  C)
             Central fringe is white and all are coloured done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer93)
  What happens to the fringe pattern when the Young?s double slit experiment is performed in water instead or air then fringe width                                                                     [AFMC 2005]
  A)
             Shrinks                                    done clear
  B)
             Disappear done clear
  C)
             Unchanged                            done clear
  D)
             Enlarged done clear
  View Solution play_arrow

• question_answer94)
  In Young?s doubled slit experiment, the separation between the slit and the screen increases. The fringe width [BCECE 2005]
  A)
             Increases                                done clear
  B)
             Decreases done clear
  C)
             Remains unchanged          done clear
  D)
             None of these done clear
  View Solution play_arrow

• question_answer95)
  In Young?s double slit experiment, the aperture screen distance is 2m. The fringe width is 1 mm. Light of 600 nm is used. If a thin plate of glass (m = 1.5) of thickness 0.06 mm is placed over one of the slits, then there will be a lateral displacement of the fringes by                                          [BCECE 2005]
  A)
             0 cm                                          done clear
  B)
             5 cm done clear
  C)
             10 cm                                       done clear
  D)
             15 cm done clear
  View Solution play_arrow

• question_answer96)
  In which of the following is the interference due to the division of wave front                                    [UPSEAT 2005]
  A)
             Young's double slit experiment done clear
  B)
             Fresnel's biprism experiment done clear
  C)
             Lloyd's mirror experiment      done clear
  D)
             Demonstration colours of thin film done clear
  View Solution play_arrow

• question_answer97)
  Two slits are separated by a distance of 0.5 mm and illuminated with light of \[\lambda =6000\]Å. If the screen is placed 2.5 m from the slits. The distance of the third bright image from the centre will be                                   [CPMT 2005]
  A)
             1.5 mm                                    done clear
  B)
             3 mm done clear
  C)
             6 mm                                        done clear
  D)
             9 mm done clear
  View Solution play_arrow