Question

Out of the following, select the correct statements:

• A. Refractive index, frequency and deviation are maximum for red colour
• B. If there were no atmosphere, the length of the day on the Earth would increase
• C. For greater value of $\mu$, the angle of deviation increases
• D. If the critical angle for the medium of a prism is ${\theta }_C$ and the angle of prism is A, there will be no emergent ray when $A<2{\theta }_C$

Answer 1

The correct option is C For greater value of $\mu$, the angle of deviation increases

For greater value of $\mu$, the angle of deviation increases because of more refraction.Refractive index is greatest for violet. Hence, angle of deviation is maximum for violet. Frequency of a light ray is not a characteristic of its color. Wavelength is the characteristic of color.

Due to atmosphere, light rays bend and reach earlier at sunrise and is visible after sunset. Hence, the day is longer due to the presence of atmosphere.

If critical angle for the medium of a prism is ${\theta }_C$, then $A>2{\theta }_C$ there will be no emergent ray.