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Topic JEE Mains · Physics · STD 12 - Ray optics and optical instruments

Microscope PYQs: JEE Mains Physics

10 STD 12 - Ray optics and optical instruments questions on Microscope, asked from 2014–2026.

10questions
248in STD 12 - Ray optics and optical instruments
2014–2026years
Difficulty mix
Easy 10% Medium 30% Hard 60%

Questions

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Showing 1–10 of 10 questions

  1. 1. In a microscope of tube length 10 cm two convex lenses are arranged with focal length of 2 cm and 5 cm . Total magnification obtained with this system for normal adjustment is \((5)^{ k }\). The value of k is _________ 2026 Easy
  2. 2. In a microscope the objective is having focal length \(f_0=2 cm\) and eye-piece is having focal length \(f_{ e }=4 cm\). The tube length is 32 cm . The magnification produced by this microscope for normal adjustment is _________ . 2026 Hard
  3. 3. In an experiment of measuring the refractive index of a glass slab using travelling microscope in physics lab, a student measures real thickness of the glass slab as \(5.25\,mm\) and apparent thickness of the glass slab at \(5.00\,mm\). Travelling microscope has \(20\) divisions in one \(cm\) on main scale and \(50\) divisions on Vernier scale is equal to \(49\) divisions on main scale. The estimated uncertainty in the measurement of refractive index of the slab is \(\frac{x}{10} \times 10^{-3}\), where \(x\) is \(..............\) 2023 Hard
  4. 4. An object viewed from a near point distance of \(25\, {cm}\), using a microscopic lens with magnification \('6',\) gives an unresolved image. A resolved image is observed at infinite distance with a total magnification double the earlier using an eyepiece along with the given lens and a tube of length \(0.6\, {m}\), if the focal length of the eyepiece is euqal to \(.... \,{cm} .\) 2021 Hard
  5. 5. Given below are two statements : one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\). Assertion \(A :\) For a simple microscope, the angular size of the object equals the angular size of the image. Reason \(R\) : Magnification is achieved as the small object can be kept much closer to the eye than \(25\, cm\) and hence it subtends a large angle. In the light of the above statements, choose the most appropriate answer from the options given below: 2021 Hard
  6. 6. 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 \(\frac{ n }{40}\, cm .\) The value of \(n\) is\(....\) 2020 Medium
  7. 7. If we need a magnification of \(375\) from a compound microscope of tube length \(150\; \mathrm{mm}\) and an objective of focal length \(5\; \mathrm{mm}\), the focal length of the eye-piece, should be close to.....\(mm\) 2020 Medium
  8. 8. In a compound microscope, the magnified virtual image is formed at a distance of \(25\, cm\) from the eye-piece. The focal length of its objective lens is \(1\, cm .\) If the magnification is \(100\) and the tube length of the microscope is \(20\, cm ,\) then the focal length of the eye-piece lens (in \(cm\) ) is 2020 Hard
  9. 9. To determine refractive index of glass slab using a travelling microscope, minimum number of readings required are 2016 Medium
  10. 10. In a compound microscope the focal length of objective lens is \(1.2\, cm\) and focal length of eye piece is \(3.0\, cm\). When object is kept at \(1.25\, cm\) in front of objective, final image is formed at infinity. Magnifying power of the compound microscope should be 2014 Hard

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How many Microscope questions came in JEE Mains?

10 questions from 2014–2026, each with the correct answer and a full solution.

How difficult are Microscope questions?

10% are easy, 30% medium and 60% hard.