Question 1:
difficultIn the Young’s double slit experiment using a monochromatic light of wavelength λ , the path
difference ( in terms of an integer n) corresponding to any point having half the peak
intensity is
Practice NEET Wave Optics Questions
Question 2:
difficultTwo polaroids are placed in the path of unpolarised beam of intensity I0 such that no light is emitted from the second polarioid. If a third polaroid whose polarization axis makes an angle θ with the polarization axis of first polaroid, is placed between these polaroids then the intensity of light emerging from the last polaroid will be :
Question 3:
difficultWhite light is used to illuminate the two silts in a Young’s double slit experiment. The separation between the slits is b and the screen is at a distance d (> > b) from the slits. At a point on the screen directly in front of one of the slits, certain wavelengths are missing. Some of these missing wavelengths are :
Question 4:
difficultThe intensity at the maximum in a Young’s double slit experiment is $I_0$. Distance between two slits is $d = 5\lambda$, where $lambda$ is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance $D = 10d$?
(2016-I)
The point in front of one slit has $y = d/2$. The path difference is $Delta x = frac{yd}{D} = frac{(d/2)d}{10d} = frac{d}{20}$. Since $d = 5lambda$, $Delta x = frac{5lambda}{20} = frac{lambda}{4}$. The phase difference is $Deltaphi = frac{2pi}{lambda} Delta x = frac{pi}{2}$. The intensity is $I = I_0 cos^2(frac{Deltaphi}{2}) = I_0 cos^2(frac{pi}{4}) = frac{I_0}{2}$.