Electromagnetic waves emanating from a point A (in air) are incident on a rectangular block of material M and emerge from the other side as shown. The angles i and r are angles of incidence and refraction when the wave travels from air to the medium. Such paths for the rays are possible

Options

A. If the material has a refractive index very nearly equal to zero
B. Only with gamma rays with a wavelength smaller than atomic nuclei of the material
C. If the material has a refractive index less than zero
D. If the material has a refractive index less than zero

Answer

C

Explanation

It is possible for negative `mu` only and materials are known as meta materials.