Waves Optics  MCQs

MCQs of Waves Optics

Showing 31 to 40 out of 131 Questions
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31.
Detailed information can be obtained by an oil immersion objective of a microscope, because the objective has _____.
(a) large value of magnification
(b) greater value of resolution
(c) large diameter
(d) None of the above
Answer:

Option (b)

32.
In a Young's double slit experiment, distance between the 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 the light used ?
(a) 5000 Å
(b) 6000 Å
(c) 7000 Å
(d) 9000 Å
Answer:

Option (b)

33.
When one of the slits of Young's experiments is covered with a transparent sheet of thickness 4.8 mm, the central fringe shifts to a position originally occupied by the 30th bright fringe. What should be the thickness of the sheet, if the central fringe has to shift to the position occupied by the 20th bright fringe ?
(a) 1.6 mm
(b) 3.2 mm
(c) 6.4 mm
(d) 9.6 mm
Answer:

Option (b)

34.
In Young's double slit experiment, two slits are 0.2 mm apart. The interference fringes for light of wavelength 6000 Å are formed on the screen 800 mm away. The distance of the fifth dark fringe, from the central fringe will be _____
(a) 2.8 mm
(b) 4.8 mm
(c) 6.8 mm
(d) 10.8 mm
Answer:

Option (d)

35.
In a YDSE both slits produce equal intensities on the screen. A 100% transparent thin film is placed in front of one of the slits. Now the intensity of the geometrical centre of the system on the screen becomes 75% of the previous intensity. The wavelength of the light is 6000 Å and μglass=1.5. The thickness of the film will be _____.
(a) 0.2 μm
(b) 1.0 μm
(c) 1.4 μm
(d) 1.6 μm
Answer:

Option (a)

36.
The light of wavelength 6328 Å is incident on a slit of width 0.2 mm perpendicularly, the angular width of central maxima (in degree) will be _____
(a) 0.36°
(b) 0.18°
(c) 0.72°
(d) 0.09°
Answer:

Option (a)

37.
In a standard Young's double slit experiment performed with light of a single wavelength, it is observed that the difference between the intensity at the maximum and the minimum is 13 of the maximum intensity. If this is due to a difference in the amplitude of the light wave emerging from each slit, the ratio of the amplitudes is _____.
(a) 3 : 1
(b) 3 : 2
(c) 2 : 1
(d) None of the above
Answer:

Option (d)

38.
The phenomenon of diffraction can be observed, when the obstacle is _____.
(a) quite large as compared to the wavelength of light used
(b) quite small as compared to the wavelength of light used
(c) of the same order as the wavelength of light used
(d) bears no relation with the wavelength of light used
Answer:

Option (c)

39.
In a Fraunhoffer diffraction experiment, the screen is at a distance of 1.0 m and an aperture of 0.30 mm diameter illuminated by light of wavelength 6000 Å. The distance of first maxima from the central fringe is _____.
(a) 6 mm
(b) 1.2 mm
(c) 3 mm
(d) 0.3 mm
Answer:

Option (c)

40.
The phenomenon of diffraction can be treated as the phenomenon of interference, if the number of coherent sources are _____.
(a) one
(b) two
(c) zero
(d) infinite
Answer:

Option (d)

Showing 31 to 40 out of 131 Questions
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