NEET UG PHYSICS MCQ: RAY OPTICS

1 Medium

1 of 1

Application +4 | -1

In a given direction, the intensities of the scattered light by a scattering substance for two beams of light are in the ratio of

256:81

. The ratio of the frequency of the first beam to the frequency of the second beam is

View answer and explanation

Correct option: B

4:3

Option B is correct because according to Rayleigh's scattering law, the intensity of scattered light is inversely proportional to the fourth power of the wavelength. Since wavelength is inversely proportional to frequency, the intensity is directly proportional to the fourth power of the frequency. Therefore, the ratio of frequencies is the fourth root of the intensity ratio, which is (256/81)^(1/4) = 4/3.

More Questions from RAY OPTICS

Practice All Chapter MCQs →

An object 5 cm tall is placed

\mathrm{1}\,\,\mathrm{m}

from a concave spherical mirror which has a radius of curvature of

\mathrm{20}\,\,\,\mathrm{cm}

. The size of the image is Red colour is used for danger signals because A ray of light is incident on the hypotenuse of a right-angled prism after travelling parallel to the base inside the prism. If

\mathrm{\mu }

is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from the hypotenuse is Statement-A: The minimum distance between an object and its real image formed by a convex lens is

2{f}

.

Statement-B: The distance between an object and its real image is minimum when its magnification is -1. Assertion: We cannot produce a real image by plane or convex mirrors under any circumstances.
Reason: The focal length of a convex mirror is always taken negative. If both the object and image are at infinite distance from a refracting telescope its magnifying power will be equal to