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CUET · PHYSICS · PYQ PAPER 2025

Rohit has been given two converging lenses of focal lengths 1.25 cm and 5 cm, respectively to design a compound microscope. If it is desired to have a magnification of 30, what would be the separation between the objective and the eyepiece when the final image is formed at the least distance of distinct vision?

  1. A 5.0 cm
  2. B 7.50 cm
  3. C 6.25 cm
  4. D 4.30 cm
Verified Solution

Answer & Solution

Correct Answer

(C) 6.25 cm

Step-by-step Solution

Detailed explanation

\(M_e = 1 + \frac{D}{f_e}\) \(M_e = 1 + \frac{25}{5} = 6\) \(M = \frac{L}{f_o} M_e\) \(30 = \frac{L}{1.25} \times 6\) \(L = \frac{30 \times 1.25}{6} = 6.25 \text{ cm}\)