Class 12 Wave Optics CBSE Questions & Answers

Class 12 · Wave Optics

This is Physics Class 12 Wave Optics CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
The angle of incidence at which the reflected beam is fully polarized is called
  • A
    critical angle
  • B
    Acute angle
  • C
    Malus angle
  • D
    Brewster angle
    Correct
2
What speed should a galaxy move with respect to us so that the sodium line at 589.0 nm is observed at 589.6 nm?
  • A
    326 km/s
  • B
    336 km/s
  • C
    306 km/s
    Correct
  • D
    356 km/s
3
Two slits are made one millimetre apart and the screen is placed one metre away. What is the fringe separation when bluegreen light of wavelength 500 nm is used?
  • A
    0.6 mm
  • B
    0.65 mm
  • C
    0.56 mm
  • D
    0.5 mm
    Correct
4
A viewing screen is separated from a double-slit source by 1.2 m. The distance between the two slits is 0.030 mm. The second-order bright fringe m =2 is 4.5 cm from the center line. Wavelength of the light is
  • A
    590 nm
  • B
    620 nm
  • C
    660 nm
  • D
    560 nm
    Correct
5
A viewing screen is separated from a double-slit source by 1.2 m. The distance between the two slits is 0.030 mm. The second-order bright fringe m =2 is 4.5 cm from the center line. Distance between adjacent bright fringes is
  • A
    2.6 cm
  • B
    2.2 cm
    Correct
  • C
    2.8 cm
  • D
    2.4 cm
6
A light source emits visible light of two wavelengths: \(\lambda \) = 430 nm and \(\lambda \)' = 510 nm. The source is used in a double-slit interference experiment in which L = 1.5 m and d = 0.025 mm. separation distance between the third order bright fringes. is
  • A
    1.4 cm
    Correct
  • B
    1.8 cm
  • C
    1.6 cm
  • D
    1.7 cm
7
In a two-slit interference experiment in which the slits are 0.200 mm apart and the screen is 1.00 m from the slits. The m = 3 bright fringe is 9.49 mm from the central fringe. Wavelength of the light is
  • A
    633 nm
    Correct
  • B
    683 nm
  • C
    653 nm
  • D
    663 nm
8
Two slits are made one millimetre apart and the screen is placed one metre away. Blue green light of wavelength 500 nm. is used . what should the width of each slit be to obtain 10 maxima of the double slit pattern within the central maximum of the single slit pattern
  • A
    0 22 mm
  • B
    0 26 mm
  • C
    0 24 mm
  • D
    0 2 mm
    Correct
9
Assume that light of wavelength 6000 \(\mathop A\limits^0 \) is coming from a star. What is the limit of resolution of a telescope whose objective has a diameter of 100 inch?
  • A
    2.6 \( \times {\rm{ 1}}{0^{ - {\rm{7}}}}{\rm{rad}}\)
  • B
    2.7 \( \times {\rm{ 1}}{0^{ - {\rm{7}}}}{\rm{rad}}\)
  • C
    2.9 \( \times {\rm{ 1}}{0^{ - {\rm{7}}}}{\rm{rad}}\)
    Correct
  • D
    2.8 \( \times {\rm{ 1}}{0^{ - {\rm{7}}}}{\rm{rad}}\)
10
For what distance is ray optics a good approximation when the aperture is 3 mm wide and the wavelength is 500 nm?
  • A
    15 m
  • B
    18 m
    Correct
  • C
    16 m
  • D
    17 m
11
Monochromatic light of wavelength 589 nm is incident from air on a water surface. What is the wavelength and speed of reflected light?
  • A
    589 nm, 3 \( \times {\rm{ 1}}{0^{\rm{8}}}\) m/s
    Correct
  • B
    590 nm, 3 \( \times {\rm{ 1}}{0^{\rm{8}}}\) m/s
  • C
    582 nm, \( \times {\rm{ 1}}{0^{\rm{8}}}\) m/s
  • D
    599 nm, \({\rm{3 }} \times {\rm{ 1}}{0^{\rm{8}}}\)m/s
12
Monochromatic light of wavelength 589 nm is incident from air on a water surface. What is the wavelength and speed of refracted light? Refractive index of water is 1.33.
  • A
    494 nm, 2.26 \({\rm{2}}.{\rm{26 }} \times {\rm{ 1}}{0^{\rm{8}}}\) m/s V 60 Hz
  • B
    484 nm, \({\rm{2}}.{\rm{26 }} \times {\rm{ 1}}{0^{\rm{8}}}\)m/s
  • C
    464 nm, 2.26 \( \times {\rm{ 1}}{0^{\rm{8}}}\) m/s
  • D
    444 nm, 2.26 \( \times {\rm{ 1}}{0^{\rm{8}}}\) m/s
    Correct
13
Shape of the wave front of light diverging from a point source is
  • A
    hyperboloid
  • B
    plane
  • C
    spherical
    Correct
  • D
    conical
14
Shape of the wave front of light emerging out of a convex lens when a point source is placed at its focus.
  • A
    plane
    Correct
  • B
    hyperboloid
  • C
    spherical
  • D
    conical
15
Shape of the wave front of portion of the wave front of light from a distant star intercepted by the Earth
  • A
    spherical
  • B
    conical
  • C
    hyperboloid
  • D
    plane
    Correct