Question Detail

PHY 104 Refraction Through Lenses and Optical Instruments Objective Question
Take CBT

Question

According to the Lensmaker's Equation, if a lens is turned around so that light impinges on the other surface, its focal length will:
Options
A Double.
B Halve.
C Remain the same.
Correct Answer
D Become negative.
Correct Answer

Option C is the correct answer.

Detailed Explanation

Page 25 states: 'The equation is symmetrical in R₁ and R₂. Thus, if a lens is turned around so that light impinges on the other sur face, the focal length is same even if the two lens sur faces are different.'

Hint

The equation involves the radii of curvature. Consider if reversing the lens changes these radii in a way that affects the overall focal length.

Question Info

Course: PHY 104
Topic: Refraction Through Lenses and Optical Instruments
Type: Objective
Difficulty: Not specified
Question 68 of 947
Previous Course Details Next