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PHY 104 Refraction Through Lenses and Optical Instruments Objective Question
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Question

If a converging glass lens, initially in air, is immersed in water (which has a higher index of refraction than air), what generally happens to its focal length?
Options
A It increases, and the lens becomes less powerful.
Correct Answer
B It decreases, and the lens becomes more powerful.
C It remains the same, as focal length is an intrinsic property.
D It becomes negative, making the lens diverging.
Correct Answer

Option A is the correct answer.

Detailed Explanation

The example on page 28 demonstrates that immersing the lens in water changes the effective refractive index ratio. The ratio (n_lens/n_medium) decreases, making the lens less effective at bending light, which results in an increased focal length and reduced power.

Hint

The bending power of a lens depends on the difference in refractive indices between the lens material and the surrounding medium.

Question Info

Course: PHY 104
Topic: Refraction Through Lenses and Optical Instruments
Type: Objective
Difficulty: Not specified
Question 112 of 947
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