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Saturday, 31 October

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 aa, at an angular resolution of 3.0×10−73.0 \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 idea in other shifts

Asked 2× in all
  1. 28 Jun 2022, Shift 1 · Q43The aperture of the objective is 24.4 cm. The resolving power of this telescope, if a light of wavelength 2440 A˚\mathrm{\AA} is used to…EasySingle correct

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.