Waves Optics  MCQs

MCQs of Waves Optics

Showing 51 to 60 out of 131 Questions
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51.
Two Nicol prisms are first crossed and then one of them is rotated through 60°. The percentage of incident light transmitted is _____ .
(a) 1.25
(b) 25.0
(c) 37.5
(d) 50
Answer:

Option (c)

52.
In Young's double slit experiment the y co-ordinates of first minimum and 10th maxima are 3 cm and 6 cm respectively. When the YDSE apparatus is immersed in a liquid of refractive index 1.5, the corresponding y co-ordinates will be _____ .
(a) 2 cm, 7.5 cm
(b) 3 cm, 6 cm
(c) 2 cm, 4 cm
(d) 43 cm, 103 cm
Answer:

Option (c)

53.
The resolving power of telescope depends upon _____ .
(a) focal length of eye lens
(b) length of telescope
(c) focal length of objective lens
(d) diameter of objective lens
Answer:

Option (d)

54.
Large aperture telescope are used for _____ .
(a) greater resolution
(b) greater magnification
(c) ease of manufacture
(d) reducing lens aberration
Answer:

Option (a)

55.
To increase both the resolving power and magnifying power of a telescope _____.
(a) wavelength of light has to be decreased
(b) aperture of the objective has to be increased
(c) focal length of the objective has to be increased
(d) both aperture of the objective and focal length has to be increased
Answer:

Option (d)

56.
The distance between two slits in an Young's experiment is 0.2 mm. If the wavelength of light used is 5000 Å, the angular positioned of 3rd bright fringe from the central bright fringe is _____ rad.
(a) 0.075
(b) 0.75
(c) 0.0075
(d) 0.057
Answer:

Option (c)

57.
In Young's experiment the distance between two slits is 0.4 cm and the distance of the screen from the slits is 100 cm. If the wavelength of light used is 5000 Å, the distance of 4th dark fringe from the central bright fringe is _____
(a) 4.37 × 10-2 cm
(b) 4.37 mm
(c) 8.74 × 10-2 cm
(d) 8.74 mm
Answer:

Option (a)

58.
The distance between two slits in Young's experiment is 0.1 mm and the distance of the screen from the slits is 100 cm. If the wavelength of light used is 5000 Å, the width of the fringe is _____
(a) 5 mm
(b) 2.5 mm
(c) 2.5 cm
(d) 5 cm
Answer:

Option (b)

59.
In Young's experiment the distance between the two slits is halved and the distance between the screen and slits is doubled. The width of the fringe _____
(a) remains the same
(b) becomes half
(c) becomes double
(d) becomes 4 times
Answer:

Option (d)

60.
A diffraction is formed with red light. If red light is replaced by blue light, _____
(a) the pattern does not change.
(b) the maxima and minima are narrow and more crowded.
(c) the maxima and minima are broadened and become distinct.
(d) diffraction pattern disappears.
Answer:

Option (b)

Showing 51 to 60 out of 131 Questions
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