Emergency Telecommunicator Certification Practice Exam

Is it true that radio waves are low energy because their wavelengths are very short?

1. True

2. False

3. Only for certain types of waves

4. Only in urban environments

The correct answer is: False

Radio waves are not considered low energy because of their short wavelengths; rather, they are characterized by long wavelengths. The energy of electromagnetic waves, including radio waves, is inversely related to their wavelength—the longer the wavelength, the lower the energy. Radio waves can have wavelengths ranging from about 1 millimeter to 100 kilometers, which places them on the lower end of the electromagnetic spectrum in terms of energy. The concept here is based on the relationship expressed in the equation E = h * f, where E is energy, h is Planck’s constant, and f is frequency. Since radio waves have low frequencies, their associated energy is also low, but it is not because they possess short wavelengths. Thus, the assertion that radio waves are low energy due to their short wavelengths is inaccurate. Radio waves are typically viewed as having longer wavelengths, granting them lower energy compared to other types of electromagnetic radiation, such as gamma rays or X-rays.