Radio waves and microwaves frequencies range from ….
A. 3 to 300kHz
B. 300kHz to 300GHz
C. 3kHz to 300GHz
D. 3kHz to 3000GHz

Hint: Radio waves and microwaves are part of the electromagnetic spectrum. As compared to other waves such as gamma or ultraviolet waves, they have lesser amounts of energies. In addition to this, the wavelengths of microwaves and radio waves are larger than that of visible light and hence their frequency is comparatively low.

Complete step by step answer:
The electromagnetic spectrum is the range of frequencies, wavelengths as well as photon energies covering frequencies from below 1 Hz up to 1025 Hz. The entire range of electromagnetic spectrum consists of radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, gamma rays and cosmic rays which are in the increasing order of frequency and decreasing order of wavelength.

Radio: A radio basically captures radio waves which are transmitted by the radio stations. Radio waves can also be emitted by the gases as well as the stars in space. Radio waves are mainly used for the communication sector. The radio waves have the lowest frequencies which are of the order of 3 kHz.

Microwave: This type of radiation is found in microwaves and helps in cooking appliances. It can also be used by astronomers to determine and understand the structures of nearby galaxies and stars. Microwaves come next to radio waves with the frequencies of the order of 300GHz.

Hence option C is the correct answer.

Note:The reason why visible light can't travel through walls as easily as gamma rays or radio waves is because the wavelengths of gamma rays are too small and fast to interact with and the radio waves are too large and slow. Exposure to very high levels of radio frequency radiation can be harmful due to the ability of Radio frequency energy to heat biological tissue rapidly.