Question

Explain the following, giving proper reason : (a) During charging of a capacitor, displacement current exists in the capacitor. But there is no displacement current when it gets fully charged. (b) The frequency of microwaves in ovens matches with the resonant frequency of water molecules. (c) Infrared waves are also known as heat waves.

How are infrared waves produced? Why are these waves referred to as heat waves? Give any two uses of infrared waves.

Name the electromagnetic waves which are produced by the following: (i) Radioactive decays of nucleus (ii) Welding arcs (iii) Hot bodies Write one use each of these waves.

Write two uses of any two of these radiation.