optical instruments questions with solutions

Showing 1–3 of 3 questions

• MCQeasyGeometrical opticsoptical instruments

  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 5ᵏ. The value of k is_____

  Options

  • Option A

    2

  • Option B

    5

  • Option C

    3.5

  • Option D

    4

  Check answerShow answer

  JEE Mains 202624 January Morning Shift

  Open question & full solution →
• MCQmediumGeometrical opticsoptical instruments

  A compound microscope uses two symmetric biconvex lenses as objective and eyepiece. The objective lens is cut by a plane perpendicular to its principal axis, producing two identical plano-convex lenses, and one of these halves is used as the new objective. If the object distance is kept unchanged, how should the tube length be changed to retain the same magnifying power?

  Options

  • Option A

    It must be doubled

  • Option B

    It must be increased by a factor 3 ÷ 2

  • Option C

    It must be halved

  • Option D

    It must be decreased by a factor 3 ÷ 2

  Check answerShow answer

  JEE Mains 2026 5 April Morning Shift

  Open question & full solution →
• NumericeasyGeometrical opticsoptical instruments

  In a microscope the objective is having focal length f₀ = 2 cm and eye-piece is having focal length fₑ = 4 cm. The tube length is 32 cm. The magnification produced by this microscope for normal adjustment is ___________.

  Your answer

  Check answerShow answer

  JEE Mains 202621 January Morning Shift

  Open question & full solution →