Assertion: Critical angle is minimum for viol | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The critical angle $	heta_c$ is given by the formula $	heta_c = \sin^{-1} \left( \frac{1}{\mu} ight)$.According to Cauchy's dispersion formula

Vedclass · Accepted Answer

If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.

Vedclass · Answer

(A) The critical angle $	heta_c$ is given by the formula $	heta_c = \sin^{-1} \left( \frac{1}{\mu} ight)$.According to Cauchy's dispersion formula,the refractive index $\mu$ of a medium is inversely proportional to the square of the wavelength $\lambda$ (approximately $\mu \propto \frac{1}{\lambda}$ for visible light).Since the wavelength of violet light is the minimum among visible colors,the refractive index $\mu$ for violet light is the maximum.As $	heta_c = \sin^{-1} \left( \frac{1}{\mu} ight)$,a higher value of $\mu$ results in a smaller value of $	heta_c$.Therefore,the critical angle is minimum for violet color. Both the Assertion and the Reason are correct,and the Reason correctly explains the Assertion.

Assertion: Critical angle is minimum for violet colour.
Reason: Because critical angle $\theta_c = \sin^{-1} \left( \frac{1}{\mu} \right)$ and $\mu \propto \frac{1}{\lambda}$.

Similar Questions

$A$ ray of light enters from air into a denser medium of refractive index $\mu = \frac{4}{3}$,as shown in the figure. The light ray undergoes total internal reflection at the adjacent surface as shown. The maximum value of angle $\theta$ should be equal to -

Assertion $(A)$: Propagation of light through an optical fibre is due to total internal reflection taking place at the core-clad interface.
Reason $(R)$: Refractive index of the material of the core of the optical fibre is greater than that of air.

$A$ beam of light consisting of red,green and blue colours is incident on a right-angled prism. The refractive index of the material of the prism for the above red,green and blue wavelengths are $1.39, 1.44$ and $1.47$ respectively.
The prism will

The critical angle is $\theta$ for light going from medium $P$ to medium $Q$. If the speed of light in medium $P$ is $V_{P}$,then the speed of light in medium $Q$ is:

Which of the following is used in optical fibres?

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Assertion: Critical angle is minimum for violet colour.Reason: Because critical angle $\theta_c = \sin^{-1} \left( \frac{1}{\mu} \right)$ and $\mu \propto \frac{1}{\lambda}$.