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Friday, 9 October

JEE Main 2025 · PhysicsMultiple choiceSingle correctMediumApplication

JEE Main 2 April 2025, Shift 2, Physics Q37

Question 37 of 75 in this shift, Physics question 12 of 25, Section A.

A bi-convex lens has radius of curvature of both the surfaces same as 1/61/6 cm. If this lens is required to be replaced by another convex lens having different radii of curvatures on both sides (R1≠R2)(R_1 \neq R_2), without any change in lens power then possible combination of R1R_1 and R2R_2 is :
  1. (1)16\frac{1}{6} cm and 19\frac{1}{9} cm
  2. (2)13\frac{1}{3} cm and 13\frac{1}{3} cm
  3. (3)15\frac{1}{5} cm and 17\frac{1}{7} cmOfficial answer
  4. (4)13\frac{1}{3} cm and 17\frac{1}{7} cm

Official answer

Option 3

NTA final key.

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

Same idea in other shifts

Asked 5× in all
  1. 2 Apr 2026, Shift 2 · Q49If sunlight is focused on a paper using convex lens, it starts burning the paper in shortest time when the lens is kept at 30 cm above the…EasyNumerical value
  2. 4 Apr 2026, Shift 2 · Q41A convex lens is made from glass material having refractive index of 1.4 with same radius of curvature on both sides. The ratio of its…EasySingle correct
  3. 3 Apr 2025, Shift 1 · Q42The radii of curvature for a thin convex lens are 10 cm and 15 cm respectively. The focal length of the lens is 12 cm. The refractive…EasySingle correct
  4. 6 Apr 2024, Shift 2 · Q46For the thin convex lens, the radii of curvature are at 15 cm and 30 cm respectively. The focal length the lens is 20 cm. The refractive…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 42 of the 174 JEE Main shifts held from 2017 to 2026.