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CUET · PHYSICS · PYQ PAPER 2025

The distance between a luminous object and the screen is 60 cm. A convex lens placed in between produces a three times magnified image on the screen. The focal length of the convex lens is:

  1. A 11.25 cm
  2. B 10.5 cm
  3. C 15.0 cm
  4. D 10.25 cm
Verified Solution

Answer & Solution

Correct Answer

(A) 11.25 cm

Step-by-step Solution

Detailed explanation

\(|u| + |v| = 60\) \(|v| = 3|u|\) \(4|u| = 60 \Rightarrow |u| = 15 \text{ cm}\) \(|v| = 3 \times 15 = 45 \text{ cm}\) \(\frac{1}{f} = \frac{1}{v} - \frac{1}{u} = \frac{1}{45} - \frac{1}{-15}\) \(\frac{1}{f} = \frac{1}{45} + \frac{3}{45} = \frac{4}{45}\)…