ExamBro
ExamBro
CUET · PHYSICS · PYQ PAPER 2023

An equiconvex lens has a focal length of 20 cm and its radius of curvature is 30 cm . Its refractive index is

  1. A \(\frac{3}{2}\)
  2. B \(\frac{5}{4}\)
  3. C \(\frac{7}{4}\)
  4. D \(\frac{7}{3}\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(\frac{7}{4}\)

Step-by-step Solution

Detailed explanation

\( \frac{1}{f} = (\mu - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right) \) \( \frac{1}{20} = (\mu - 1) \left( \frac{1}{30} - \frac{1}{-30} \right) \) \( \frac{1}{20} = (\mu - 1) \left( \frac{2}{30} \right) \) \( \mu - 1 = \frac{30}{2 \times 20} = \frac{3}{4} \)…
From CUET
Explore more questions on app