Question

Which band does the $3 \times {10^9}Hz$ to $3 \times {10^{10}}Hz$ frequency range fall into?
(A) High frequency band
(B) Super-high frequency band
(C) Ultra-high frequency band
(D) Very high frequency band

Answer 1

Hint
Electromagnetic spectrum is used as a standard for defining the ranges of frequencies into specific classes. The lowest frequencies start from the radio waves, and microwaves all the way up to X-rays and Gamma-rays.

Complete step by step answer
The only spectrum of electromagnetic waves that we can see is the visible spectrum. It consists of 7 major colours pertaining to different wavelengths of the visible light. But there are many more frequencies and wavelengths at which these waves operate like the radio waves, X-rays and gamma rays. The electromagnetic spectrum defines an order of the frequencies of these waves.
The first ever electromagnetic radiation other than visible light was the Infrared radiation and it was discovered by William Herschel in 1800. The classes of electromagnetic waves, as mentioned in the question, range as:
High frequency band: 3 MHz to 30 MHz
Super-high frequency band: 3GHz to 30GHz
Ultra-high frequency band: 300 MHz to 3 GHz
Very high frequency band: 30 MHz to 300 MHz
Here, $1{\text{ MHz}} = {10^6}{\text{ Hz}}$and $1{\text{ GHz}} = {10^9}{\text{ Hz}}$.
The frequency range that we need to identify in our question is 3 MHz to 30 MHz. From the above distinction we can see that this lies in the high frequency band. This also lies in the major class of radio waves.
Thus, the correct answer is option (A).

Note
 Radio waves are widely used for transmitting information through radio broadcasting stations, television, mobile phones, etc. The radio spectrum is also strictly regulated by each country’s government to provide limited and accountable access to all service providers.