JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumCalculation

JEE Main 31 August 2021, Shift 1, Physics Q6

Question 6 of 90 in this shift, Physics question 6 of 30, Section A.

An object is placed at the focus of concave lens having focal length

f

. What is the magnification and distance of the image from the optical centre of the lens ?

(1)Very high, $\infty$
(2) $1$ , $\infty$
(3) $\frac{1}{2}$ , $\frac{f}{2}$ Official answer
(4) $\frac{1}{4}$ , $\frac{f}{4}$

Official answer

Option 3

NTA final key.

Chapter: Ray Optics and Optical Instruments
Topic: Lens Maker's Formula
Idea tested: Thin Lens Formula

Same idea in other shifts

Asked 4× in all

9 Apr 2024, Shift 1 · Q45Given below are two statements : Statement (I) : When an object is placed at the centre of curvature of a concave lens, image is formed at…MediumTwo statements
10 Apr 2023, Shift 2 · Q57A point object, 'O' is placed in front of two thin symmetrical coaxial convex lenses $L_1$ and $L_2$ with focal length 24 cm and 9 cm…MediumNumerical valueHas a figure
25 Jul 2022, Shift 2 · Q38For an object placed at a distance 2.4 m from a lens, a sharp focused image is observed on a screen placed at a distance 12 cm form the…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.