Angular fringe width, θ=dλ,θ2θ1=d1d2
0.210.20=2d2⇒d2=0.210.20×2=1.9mm
In Young's double slit experiment the separation d between the slits is 2mm, the wavelength λ of the light used is 5896Å and distance D between the screen and slits is 100cm. It is found that the angular width of the fringes is 0.20∘. To increase the fringe angular width to 0.21o (with same λandD) the separation between the slits needs to be changed to
Held on 30 Apr 2018 · Verified 9 Jul 2026.
2.1mm
1.9mm
1.8mm
1.7mm
Sign in to track your attempts and accuracy.
Sign in to keep a private note on this question. Nothing you write is ever public.
The refractive index of glass is 1.5. The speed of light in glass is:
Two thin lenses of focal lengths f₁ = +20 cm and f₂ = -10 cm are in contact. The power of the combination is:
An unpolarized light beam travelling in air is incident on a medium of refractive index 1.73 at Brewster's angle. Then -
A microscope has an objective of focal length 2 cm , eyepiece of focal length 4 cm and the tube length of 40 cm . If the distance of distinct vision of eye is 25 cm , the magnification in the microscope is :
The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at $22.5^{\circ}$ from the polarization axis of one of the polaroid, is ( $\mathrm{I}_0$ is the intensity of polarised light after passing through the first polaroid):
Work through every NEET UG Optics PYQ, year by year.