Question

Show the electromagnetic wave by a diagram and write down its three important properties. Which radiation has the least wavelength in the spectrum of electromagnetic waves?

Hint:

Remember, in the electromagnetic spectrum, the wavelength decreases and frequency increases as we move from radio waves to gamma rays. Gamma rays have the least wavelength and the highest frequency.

Answer 1

An electromagnetic wave consists of oscillating electric and magnetic fields that are perpendicular to each other and to the direction of propagation of the wave. These waves travel at the speed of light (\( c = 3 \times 10^8 \, \text{m/s} \)) in a vacuum. The electric field \( \mathbf{E} \) and magnetic field \( \mathbf{B} \) oscillate in phase, and their energy is transferred through the space. The diagram for an electromagnetic wave is shown below: In the diagram: - The electric field (\( \mathbf{E} \)) oscillates in one plane (perpendicular to the direction of wave propagation). - The magnetic field (\( \mathbf{B} \)) oscillates in a plane perpendicular to the electric field, and also perpendicular to the direction of wave propagation. - The wave propagates in the direction perpendicular to both the electric and magnetic fields. Three Important Properties of Electromagnetic Waves:
1. Transverse Nature: Electromagnetic waves are transverse waves, meaning the oscillations of the electric and magnetic fields are perpendicular to the direction of wave propagation.
2. Speed of Light: In a vacuum, electromagnetic waves travel at a constant speed of \( c = 3 \times 10^8 \, \text{m/s} \).
3. Electromagnetic Spectrum: Electromagnetic waves encompass a wide range of wavelengths and frequencies, forming the electromagnetic spectrum, which includes radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. The frequency and wavelength of an electromagnetic wave are related by: \[ c = \lambda \times \nu \] Where: - \( c \) is the speed of light (\( 3 \times 10^8 \, \text{m/s} \)), - \( \lambda \) is the wavelength, - \( \nu \) is the frequency.
Which Radiation Has the Least Wavelength?
Gamma rays have the least wavelength in the electromagnetic spectrum. They have the highest frequency and the most energy compared to other types of electromagnetic radiation. The wavelength of gamma rays can be as small as \( 10^{-12} \, \text{m} \), making them the most penetrating form of electromagnetic radiation.