Monochromatic light is refracted from air into glass of refractive index $\mu$. The ratio of the wavelength of incident and refracted waves is

If light passes near a massive object,the gravitational interaction causes a bending of the ray. This can be thought of as happening due to a change in the effective refractive index of the medium given by $n = 1 + \frac{2GM}{rc^2}$,where $r$ is the distance of the point of consideration from the centre of the mass of the massive body,$G$ is the universal gravitational constant,$M$ is the mass of the body,and $c$ is the speed of light in vacuum. Considering a spherical object,find the deviation of the ray from the original path as it grazes the object.

$A$ red colour in air has a wavelength of $760 \,nm$. When light passes through water of refractive index $n = \frac{4}{3}$,its wavelength becomes $570 \,nm$. (The wavelength of yellow colour in air is $570 \,nm$). The colour of the red light in water is:

An observer can see through a pin-hole the top end of a thin rod of height $h$,placed as shown in the figure. The beaker height is $3h$ and its radius is $h$. When the beaker is filled with a liquid up to a height $2h$,the observer can see the lower end of the rod. Then the refractive index of the liquid is

$A$ beam of light propagating in medium $A$ with index of refraction $n(A)$ passes across an interface into medium $B$ with index of refraction $n(B)$. The angle of incidence is greater than the angle of refraction; $v(A)$ and $v(B)$ denote the speed of light in $A$ and $B$. Then which of the following is true?

$A$ ray of light passes through four transparent media with refractive indices $\mu_1, \mu_2, \mu_3$ and $\mu_4$ as shown in the figure. The surfaces of all media are parallel. If the emergent ray $CD$ is parallel to the incident ray $AB$,we must have