Question

Name the parts of the electromagnetic spectrum which are (i) also known as 'heat waves' and (ii) absorbed by ozone layer in the atmosphere.

A plane light wave propagating from a rarer into a denser medium, is incident at an angle i on the surface separating two media. Using Huygen's principle, draw the refracted wave and hence verify Snell's law of refraction.

State Huygens principle. Using it draw a diagram showing the details of passage of a plane wave from a denser into a rarer medium.

Assertion (A) : The phase difference between any two points on a wavefront is zero. Reason (R) : All points on a wavefront are at the same distance from the source and thus oscillate in the same phase.