A prism is an optical medium bounded by three refracting plane surfaces. A ray of light suffers successive refractions on passing through its two…

A prism is an optical medium bounded by three refracting plane surfaces. A ray of light suffers successive refractions on passing through its two surfaces and deviates by a certain angle from its original path. The refractive index of the material of the prism is given by $\displaystyle \mu=\sin \left(\frac{\mathrm{A}+\delta \mathrm{m}}{2}\right) / \sin \frac{\mathrm{A}}{2}$. If the angle of incidence on the second surface is greater than an angle called critical angle, the ray will not be refracted from the second surface and is totally internally reflected.

The critical angle for glass is $\displaystyle \theta_{1}$ and that for water is $\displaystyle \theta_{2}$. The critical angle for glass-water surface would be (given $\displaystyle { }_{\mathrm{a}} \mu_{\mathrm{g}}=1.5$, $\displaystyle { }_{\mathrm{a}} \mu_{\mathrm{w}}=1.33$ )

less than $\displaystyle \theta_{2}$

between $\displaystyle \theta_{1}$ and $\displaystyle \theta_{2}$

greater than $\displaystyle \theta_{2}$

less than $\displaystyle \theta_{1}$

When a ray of light of wavelength $\displaystyle \lambda$ and frequency $\displaystyle v$ is refracted into a denser medium

$\displaystyle \lambda$ and $\displaystyle v$ both increase.

$\displaystyle \lambda$ increases but $\displaystyle v$ is unchanged.

$\displaystyle \lambda$ decreases but $\displaystyle v$ is unchanged.

$\displaystyle \lambda$ and $\displaystyle v$ both decrease.

A ray of light is incident normally on a prism ABC of refractive index $\displaystyle \sqrt{2}$, as shown in figure. After it strikes face AC, it will

go straight undeviated

just graze along the face AC

refract and go out of the prism

undergo total internal reflection