$A$ radar sends waves towards a distant object and receives the signal reflected by the object. These waves are:

Write the sources of visible rays and ultraviolet rays and their uses.

If wavelengths of visible rays,microwaves,and $X$-rays are $\lambda_v$,$\lambda_m$,and $\lambda_x$ respectively,then which of the following relations is correct?

$A$ bolometer is used to detect ...... .

Infrared radiations are detected by:

The radiation of frequency $1057 \ MHz$ coming from two close energy levels of hydrogen belongs to which part of the electromagnetic spectrum?