JEE PHYSICS MCQ: RAY OPTICS

1 Medium

1 of 1

Analyzing +4 | -1

Assertion: A spherical mirror of focal length

{f}

in air is used in a medium of refractive index 5 . Then the focal length of mirror in medium becomes octave.

Reason: The radius of curvature of a mirror is double of the focal length.

View answer and explanation

Correct option: D

If Assertion is false but Reason is true.

Option D (If Assertion is false but Reason is true) is correct because the focal length of a mirror is independent of the surrounding medium, and the radius of curvature is indeed twice the focal length.

More Questions from RAY OPTICS

Practice All Chapter MCQs →

In refraction, light waves are bent on passing from one medium to the second medium, because, in the second medium A double convex lens is made of glass which has its refractive index 1,45 for violet rays and 1.50 for red rays. If the focal length for violet ray is

20 \mathrm{~cm}

, the focal length for red ray will be Which light rays undergoes two internal reflection inside a raindrop, which of the rainbow is formed? A piece of plane glass is placed on a word with letters of different colours. The letters which appear minimum raised are A dentist has a small mirror of focal length

16 {~mm}

. He views the cavity in the tooth of a patient by holding the mirror at a distance of

8 {~mm}

from the cavity. The magnification is All of the following statements are correct except