Optics Question 668

Question: The focal length of lens of refractive index 1.5 in air is 30 cm. When it is immersed in a liquid of refractive index 43 , then its focal length in liquid will be

[BHU 2002]

Options:

A) 30 cm

B) 60 cm

C) 120 cm

D) 240 cm

Show Answer

Answer:

Correct Answer: C

Solution:

By using flfa=(aμg1)(lμg1)fw=4fa=4×30 =120 cm.



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