Chapter U5, Problem 16RE

Interpretation Introduction

Interpretation:

The least harmful electromagnetic radiation on the basis of wavelength, frequency and energy needs to be listed.

Concept introduction:

Electromagnetic radiations can be defined as radiations of electromagnetic field. These radiations propagate through space and have certain electromagnetic energy.

Some of the electromagnetic radiations are X-rays, Infra-red, Ultra-violet, radio waves, and microwaves.Each radiation is associated with certain energy, frequency and wavelength.

Answer to Problem 16RE

Radio waves are least harmful electromagnetic radiation due to longest wavelength and lowest energy.

Explanation of Solution

Given information:

Wavelength and frequency of radiations are related with energy.

The relation between energy, frequency and wavelength is:

$\begin{array}{l}\text{E = h × }\upsilon \text{ = }\frac{\text{h × c}}{\lambda }\\ \text{E = energy}\\ \upsilon \text{ = Frequency}\\ \text{h = Plank's constant}\\ \lambda \text{ = wavelength}\\ \text{c = Speed of light}\end{array}$

The electromagnetic spectrum represents the sequence of electromagnetic radiations from radio waves to gamma rays. Radio waves have longest wavelength of 10³ m, whereas gamma rays have shortest wavelength of 10-12 m. Thus, radio waves are least harmful due to longest wavelength.

Conclusion

The radiation with longest wavelength will have least energy.