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Saturday, 31 October

JEE Main 2020 · PhysicsNumerical answerNumerical valueMediumCalculation

JEE Main 5 September 2020, Shift 1, Physics Q24

Question 24 of 75 in this shift, Physics question 24 of 25.

A compound microscope consists of an objective lens of focal length 1 cm and an eye piece of focal length 5 cm with a separation of 10 cm. The distance between an object and the objective lens, at which the strain on the eye is minimum is n40\frac{n}{40}cm. The value of n is __________.

Official answer

50.00

NTA final key (Sep 2020).

Chapter
Ray Optics and Optical Instruments
Topic
Optical Instruments
Idea tested
Microscope Tube Length

Same idea in other shifts

Asked 2× in all
  1. 5 Apr 2026, Shift 1 · Q42A compound microscope is designed with two symmetric biconvex lenses. The objective lens is cut vertically, creating two identical…HardSingle 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.