Which of the following electromagnetic waves has the lowest energy?
A. gamma ray
B. infrared wave
C. visible light wave
D. microwave
The correct answer and explanation is :
The correct answer is D. microwave.
Explanation:
Electromagnetic waves span a wide range of frequencies and wavelengths, forming the electromagnetic spectrum. The energy carried by an electromagnetic wave is directly related to its frequency: higher frequency waves have higher energy, and lower frequency waves have lower energy. Conversely, energy is inversely related to wavelength: longer wavelength waves have lower energy, and shorter wavelength waves have higher energy.
We can order the given types of electromagnetic waves by their typical energy levels, from lowest energy to highest energy:
Microwaves: These have relatively long wavelengths and low frequencies. They are commonly used for communication and heating (like in microwave ovens).
Infrared waves: These have shorter wavelengths and higher frequencies than microwaves, but longer wavelengths and lower frequencies than visible light. We perceive them as heat.
Visible light waves: This is the narrow band of the spectrum that our eyes can detect, ranging from red (lowest energy visible light) to violet (highest energy visible light).
Gamma rays: These have the shortest wavelengths and highest frequencies of all electromagnetic waves. They carry immense amounts of energy and are produced by nuclear reactions.
Comparing the options provided, microwaves are located at the lower energy end of the spectrum compared to infrared waves, visible light waves, and gamma rays. Gamma rays are at the highest energy end. Therefore, among the choices given, microwaves have the lowest energy.