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Set 3 of 10 · Questions 61-90 of 295

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JEE Main Physics · Wave Optics · Set 3 (Q61-90)

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  1. 61.
    Calculate the limit of resolution of a telescope objectiv having a diameter of if it has to detect light wavelength coming from a star.
    1. (1)radian
    2. (2)radian
    3. (3)radian
    4. (4)radian
  2. 62.
    A beam of unpolarized light of intensity is passed through a polaroid and then through another polaroid B which is oriented so that its principal plane makes an angle of relative to that of . The intensity of emergent light is :
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  3. 63.
    An unpolarised beam of intensity falls on a polaroid. The intensity of the emergent light is
    1. (1)
    2. (2)zero
    3. (3)2
    4. (4)
  4. 64.
    In Young's double slit experiment, in an interference pattern second minimum is observed exactly in front of one slit. The distance between the two coherent sources is and the distance between source and screen is . The wavelength of light source used is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  5. 65.
    Interference fringes are observed on a screen by illuminating two thin slits apart with a light source . The distance between the screen and the slits is . If a bright fringe is observed on a screen at a distance of from the central bright fringe, then the path difference between the waves, which are reaching this point from the slits is close is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  6. 66.
    A slit of width is illuminated by red light of wavelength . If the first diffraction minimum falls at , then the value of is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  7. 67.
    Two slits are made one millimetre apart and the screen is placed one metre away from the slits. The fringe width when light of wavelength is used is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  8. 68.
    Two slits separated by a distance of are illuminated with light of wavelength . The interference fringes are observed on a screen placed at from the slits. The distance between the third dark fringe and the fifth bright fringe is equal to
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  9. 69.
    The polarising angle for transparent medium is , is the speed of light in that medium. Then the relation between and is ( velocity of light in air)
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  10. 70.
    Diameter of the objective of a telescope is . What is the resolving power of a telescope? Take wavelength of light .
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  11. 71.
    Light of wavelength is incident normally on a slit of width . The angular width of central maxima in the diffraction pattern is (measured from minimum to minimum)
    1. (1)
    2. (2)
    3. (3)2.4×rad
    4. (4)
  12. 72.
    Wave front is the locus of all points, where the particles of the medium vibrate with the same
    1. (1)phase
    2. (2)amplitude
    3. (3)frequency
    4. (4)period
  13. 73.
    In a Young's double slit experiment, light of is used to produce an interference pattern. When the distance between the slits is , the angular width (in degree) of the fringes formed on the distance screen is close to
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  14. 74.
    With the help of a telescope that has an objective of diameter , it is proved that light of wavelengths of the order of coming from a star can be easily resolved. Then, the limit of resolution is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  15. 75.
    Two wavelengths of sodium light and are used one after another to study diffraction due to single slit of aperture . The distance between the slit and the screen is . The separation between the position of first maximum of the diffraction pattern obtained in the two cases is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  16. 76.
    In Young's double slit experiment for what order does the wavelength of red light coincide with order of blue light
    1. (1)1
    2. (2)2
    3. (3)3
    4. (4)4
  17. 77.
    A monochromatic light of frequency travelling through air, is incident on a medium of refractive index ' 2 '. Wavelength of the refracted light will be:
    1. (1)400 nm
    2. (2)300 nm
    3. (3)600 nm
    4. (4)500 nm
  18. 78.
    Two coherent sources of intensity ratio produce interference. The intensity ratio of maxima and minima of the interference pattern is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  19. 79.
    The wavelength of the light used in Young's double slit experiment is . The intensity at a point on the screen where the path difference is is . If denotes the maximum intensity, then the ratio of and is
    1. (1)0.866
    2. (2)0.5
    3. (3)0.707
    4. (4)0.75
  20. 80.
    In a double-slit experiment, at a certain point on the screen the path difference between the two interfering waves is of a wavelength. The ratio of the intensity of light at that point to that at the centre of a bright fringe is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  21. 81.
    The speed of electrons in a scanning electron microscope is . If the protons having the samespeed are used instead of electrons, then the resolving power of scanning proton microscope will be changedby a factor of:
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  22. 82.
    The optical path difference between two identical light waves arriving at a point is where ' ' is the wavelength of light used. The point is [Two light sources are coherent]
    1. (1)neither bright nor dark
    2. (2)dark
    3. (3)bright
    4. (4)alternatively bright and dark.
  23. 83.
    The path difference between two interfering light waves meeting at a point on the screen is . The band obtained at that point is
    1. (1)  dark band
    2. (2)  dark band
    3. (3)  bright band
    4. (4)  bright band
  24. 84.
    A fringe width of was produced for two slits separated by apart. The screen is placed away.The wavelength of light used is . The value of ' ' to the nearest integer is____
  25. 85.
    Orange light of wavelength illuminates a single slit of width . The maximum possible number of diffraction minima produced on both sides of the central maximum is
  26. 86.
    Two coherent monochromatic light beams of intensities 4I and 9I are superimposed. The difference between the maximum and minimum intensities in the resulting interference pattern is . The value of is _______ .
  27. 87.
    A double slit interference experiment performed with a light of wavelength 600 nm forms
    an interference fringe pattern on a screen with 10 th bright fringe having its centre at a distance of 10 mm from the central maximum. Distance of the centre of the same 10th bright fringe from the central maximum when the source of light is replaced by another source of wavelength 660 nm would be mm.
  28. 88.
    A Young's double-slit experiment is performed using monochromatic light of wavelength . The intensity of light at a point on the screen, where the path difference is , is units. The intensity of light at a point where the path difference is is given by , where is an integer. The value of is
  29. 89.
    In a double slit experiment with monochromatic light, fringes are obtained on a screen placed at some distance from the plane of slits. If the screen is moved by 5 x m towards the slits, the change in fringe width is 3 x cm. If the distance between the slits is 1 mm, then the wavelength of the light will be______nm.
  30. 90.
    In Young's double slit experiment the two slits are 0.6 mm distance apart. Interference pattern is observed on a screen at a distance 80 cm from the slits. The first dark fringe is observed on the screen directly opposite to one of the slits. The wavelength of light will be_____nm.