JEE Main 2026 · PhysicsNumerical answerNumerical valueEasyCalculation

JEE Main 8 April 2026, Shift 2, Physics Q47

Question 47 of 75 in this shift, Physics question 22 of 25, Section B.

Some 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}

radian. If the wavelength of light from the star reaching the telescope is 500 nm, the minimum diameter of the objective lens of the telescope is ________ cm. (nearest interger)

Official answer

203

NTA final key.

Chapter: Wave Optics
Topic: Single Slit Diffraction
Idea tested: Resolving Power of a Telescope

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
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
8 Apr 2024, Shift 1 · Q59A parallel beam of monochromatic light of wavelength 600 nm passes through single slit of 0.4 mm width. Angular divergence corresponding…EasyNumerical value
24 Jun 2022, Shift 1 · Q55Sodium light of wavelengths 650 nm and 655 nm is used to study diffraction at a single slit of aperture 0.5 mm. The distance between the…MediumNumerical 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 42 of the 174 JEE Main shifts held from 2017 to 2026.