JEE 2020: Weekly Quiz 23 (31.08.2019) for JEE & BITSAT Exams

Question 1

Two beams, A and B. of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam A has maximum intensity (and beam B has zero intensity), a rotation of Polaroid through 30° makes the two beams appear equally bright. If the initial intensities of the two beams are I_A and I_B respectively, then I_A/ I_B equals :

Question 2

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 of wavelength 6000 Å, the fringe width (in mm) will be -

Question 3

Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio-

Question 4

Two monochromatic light waves of amplitudes A and 2A interfering at a point, have a phase difference of 60 º. The intensity at that point will be proportional to -

Question 5

If the first minima in a Young’s slit experiment occurs directly infront of one of the slits. (distance between slit & screen D = 12 cm and distance between slits d = 5 cm) then the wavelength of the radiation used is :

Question 6

Refractive index of a thin soap film of a uniform thickness is 1.34. Find the smallest thickness of the film that gives an interference maximum in the reflected light when light of wavelength 5360 Å falls at normal incidence

Question 7

The central fringe of the interference pattern produced by light of wavelength 6000 Å is found to shift to the position of 4th bright fringe after a glass plate of refractive index 1.5 is introduced in path of one of beams. The thickness of the glass plate (μm) in would be -

Question 8

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 (in mm) will be -

Question 9

The Young's double slit experiment is performed with blue and with green light of wavelengths 4360 Å and 5460 Å respectively. If X is the distance of 4^th maximum from the central one, then -

Question 10

The double slit experiment of Young has been shown in figure. Q is the position of the first bright fringe on the right side and P is the 11^th bright fringe on the other side as measured from Q. If wavelength of the light used is 6000 Å, S₁B, will be equal to -