The electromagnetic waves of frequency range 100 to 300 Hz are used in

The electromagnetic waves of frequency range 100 to 300 GHz are used in

The electromagnetic wave of frequency 3 MHz to 30 MHz are used

The electromagnetic wave is of frequency range from 5xx10^5 Hz to 10^9Hz are called..............

Find the wavelength of electromagnetic waves of frequency 5xx 10^(19) Hz in free space. Give its two applications.