Final answer:
An electromagnetic wave is composed of perpendicular and in-phase electric and magnetic fields. So, option A is correct.
Step-by-step explanation:
A wave that is comprised of electric and magnetic fields is known as an electromagnetic wave. So, the correct option is a. electromagnetic wave. An electromagnetic wave consists of electric fields (E) and magnetic fields (B) that are perpendicular to each other and the direction of wave propagation, making it a transverse wave. These fields are not only perpendicular but are also in phase with each other, meaning that the peaks and troughs of the electric field align with those of the magnetic field.
Unlike sound waves, which are mechanical and require a medium to travel through, electromagnetic waves can propagate through a vacuum at the speed of light, which is approximately 3 × 10⁸ m/s. Understanding the nature of electromagnetic waves is crucial for studying phenomena such as light and radio waves. For example, light waves and radio waves are both types of electromagnetic waves. These waves travel through space at a constant speed of approximately 3 × 10⁸ m/s. They can also travel through a medium, such as water or air, but at a slower speed.