Light travels through a glass plate of thickness t and having refractive index μ, If c be the velocity of light in vacuum, the time taken by the light to travel this thickness of glass is :

A ray of light is incident on the surface of separation of a medium at an angle 45° and is refracted in the medium at an angle 30°, What will be the velocity of light in the medium ?

A ray of light passes through four transparent media with refractive indices μ1, μ2, μ3 and μ4 as shown in the given figure.
The surfaces of all media are parallel. If the emergent ray CD is parallel to the incident ray AB, we must have :

Two mirrors at an angle θ produce 5 images of a point. The number of images produced when θ is decreased to 30° is

Two plane mirrors A and B are aligned parallel to each other, as shown in the figure. A light ray is incident at an angle of 30° at a point just inside one end of A. The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflections (including the first one) before it emerges out is :

If the lower half of a concave mirror’s reflecting surface is made opaque, which of the following statements describe the image of an object placed in-front of the mirror

S1 : Intensity of the image will increase.
S2 : The image will show only half of the object.
S3 : No change in the image.
S4 : Intensity of the image will be reduced to half.

Match the corresponding entries of column-1 with coloumn-2 (Where m is the magnification produced by the mirror) :

How much water should be filled in a container 21 cm in height, so that it appears half filled when viewed from the top of the container
(given that \[_{\alpha}\mu_{\omega} =4/3\])

A rectangular tank of depth 8 meter is full of water (μ = 4/3), the bottom is seen at the depth

A beam of light is converging towards a point I on a screen. A plane glass plate whose thickness in the direction of the beam = t, refractive index = μ, is introduced in the path of the beam. The convergence point is shifted by