The refracted wavefront of the plane wavefront from prism will be wavefront which is inclined to the incident plane.

How fast would a rocket have to go relative to an observer for its length to be corrected to $99\%$ of its length at rest? $\left(\mathrm{c}=3\times {10}^8{\mathrm{ms}}^{-1}\right)$

When light travels from a rarer to a denser medium, it loses speed. Does this loss imply a reduction in energy carried by the light waves?

What is the geometrical shape of the wave front when a plane wave passes through a convex lens?

A monochromatic plane wave of speed c and wavelength $\lambda$ is diffracted at a small aperture. The diagram illustrates successive wavefronts (vibrating in same phase). After what time will some portion of the wavefront $XY$ reach $P$?

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

Does the speed of light in an isotropic medium, depend upon (i) nature of source, (ii) direction of propagation, (iii) intensity of the wave, (iv) motion of the source/observer, (v) wavelength?