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Friday, 9 October

JEE Main 2026 · PhysicsMultiple choiceSingle correctMediumMulti-step

JEE Main 8 April 2026, Shift 2, Physics Q30

Question 30 of 75 in this shift, Physics question 5 of 25, Section A.

A thin biconvex lens is prepared from the glass (μ=1.5\mu = 1.5) both curved surfaces of which have equal radii of 20 cm each. Left side surface of the lens is silvered from outside to make it reflecting. To have the position of image and object at the same place, the object should be placed, from the lens at a distance of ________ cm.
  1. (1)10Official answer
  2. (2)12.5
  3. (3)13
  4. (4)13.5

Official answer

Option 1

NTA final key.

Chapter
Ray Optics and Optical Instruments
Topic
Lens Maker's Formula
Idea tested
Silvering of Lens Surface

Same topic in other shifts

All Lens Maker's Formula questions
  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. 5 Apr 2026, Shift 2 · Q40A thin convex lens and a thin concave lens are kept in contact and are co-axial. Which of the following statements is correct for this…EasySingle correct
  4. 5 Apr 2026, Shift 2 · Q41An object ABAB is placed 15 cm on the left of a convex lens PP of focal length 10 cm. Another convex lens QQ is now placed 15 cm right…MediumSingle correct
  5. 2 Apr 2025, Shift 1 · Q41A slanted object AB is placed on one side of convex lens as shown in the diagram. The image is formed on the opposite side. Angle made by…HardDiagram basedHas a figure
  6. 2 Apr 2025, Shift 2 · Q37A 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…MediumSingle 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.