JEE Main 2020 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 9 January 2020, Shift 1, Physics Q16

Question 16 of 75 in this shift, Physics question 16 of 25, Section A.

The aperture diameter of a telescope is 5 m. The separation between the moon and the earth is

4\times10^{5}

km. With light of wavelength of 5500

\mathrm{\AA}

, the minimum separation between objects on the surface of moon, so that they are just resolved, is close to :

(1) $20$ m
(2) $60$ mOfficial answer
(3) $200$ m
(4) $600$ m

Official answer

Option 2

NTA final key (Jan 2020).

Chapter: Wave Optics
Topic: Single Slit Diffraction
Idea tested: Rayleigh Criterion

Same topic in other shifts

All Single Slit Diffraction questions

2 Apr 2026, Shift 1 · Q46In single slit diffraction pattern, the wavelength of light used is $628$ nm and slit width is $0.2$ mm, the angular width of central…EasyNumerical value
4 Apr 2026, Shift 1 · Q33A slit of width $a$ is illuminated by light of wavelength $\lambda$ . The linear separation between $1^{\text{st}}$ and $3^{\text{rd}}$ …EasySingle correct
8 Apr 2026, Shift 2 · Q47Some distant star is to be observed by some telescope of diameter of objective lens $a$ , at an angular resolution of $3.0 \times 10^{-7}$ …EasyNumerical value
2 Apr 2025, Shift 1 · Q50If the measured angular separation between the second minimum to the left of the central maximum and the third minimum to the right of the…MediumNumerical value
4 Apr 2025, Shift 2 · Q46In a Young's double slit experiment, two slits are located 1.5 mm apart. The distance of screen from slits is 2 m and the wavelength of…MediumNumerical value
5 Apr 2024, Shift 2 · Q53In a single slit experiment, a parallel beam of green light of wavelength 550 nm passes through a slit of width 0.20 mm. The transmitted…EasyNumerical value

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.