The electron beam will be diffractive at an angle θ
For Ist minima
dsinθ=λ
dsinθ=ph
Also psinθ=py
⇒dpy=h
∴ majority of electrons passing through the slit are lying in the central maxima dpy<h
A parallel beam of electrons travelling in x - direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires…
JEE Main 2015 — Physics Optics
2015mcqhard
A parallel beam of electrons travelling in x - direction falls on a slit of width d (see figure). If after passing the slit, an electron acquires momentum py in the y - direction then for a majority of electrons passing through the slit (h is Planck's constant):
Official previous-year question
Held on 10 Apr 2015 · Verified 6 Jul 2026.
Options
- A
∣py∣d<h
- B
∣py∣d>h
- C
∣py∣d≃h
- D
∣py∣d>>h
Did you get this right?
Sign in to track your attempts and accuracy.
Your note
Sign in to keep a private note on this question. Nothing you write is ever public.
JEE Main Optics in other years
More JEE Main Optics questions
When an unpolarized light falls at a particular angle on a glass plate (placed in air), it is observed that the reflected beam is linearly polarized. The angle of refracted beam with respect to the normal is $\_\_\_\_$. $\left(\tan ^{-1}(1.52)=57.7^{\circ}\right.$, refractive indices of air and glass are 1.00 and 1.52, respectively.)
2026medium
A ray of light passing through an equilateral prism is having velocity $2.12 \times 10^8$ m/s in the prism material, then the minimum angle of deviation is _________ degrees.
2026medium
In a Young double slit experiment, the wavelength of incident light is $6000$ Å, the separation between slits $S_1$ and $S_2$ is $5$ cm and the distance between slits plane and screen is $50$ cm, as shown in the figure below. If the resultant intensity at $P$ is equal to the intensity due to individual slits, the path difference between interfering waves is __________ Å. 
2026medium
In two separate Young's double-slit experimental set-ups and two monochromatic light sources of different wavelengths are used to get fringes of equal width. The ratios of the slits separations and that of the wavelengths of light used are $2: 1$ and $1: 2$ respectively. The corresponding ratio of the distances between the slits and the respective screens ($D_{1} / D_{2}$) is $\_\_\_\_$.
2026medium
If sunlight is focused on a paper using convex lens, it starts burning the paper in shortest time when the lens is kept at $30$ cm above the paper. If the radius of curvature of the lens is $60$ cm then the refractive index of the lens material is $\dfrac{\alpha}{10}$. The value of $\alpha$ is _______.
2026medium
Other Physics topics for JEE Main
Keep practicing Optics
Work through every JEE Main Optics PYQ, year by year.