What exactly is the power of electromagnetic radiation?

In physics, power is defined as the rate of transfer of energy. Electromagnetic waves (like any other wave) transfers energy from one location to another. read more

For electromagnetic waves this is usually quantified as the Poynting vector which gives you the power per unit area. The magnitude of the Poynting vector depends on the electric and magnetic fields that the electromagnetic radiation is composed of. read more

Electromagnetic radiation is a transverse wave, meaning that its oscillations are perpendicular to the direction of energy transfer and travel. The electric and magnetic parts of the field stand in a fixed ratio of strengths in order to satisfy the two Maxwell equations that specify how one is produced from the other. read more

Electromagnetic (EM) radiation is the movement of energy - through space or a medium - composed of both electric and magnetic waves. These waves oscillate at frequencies that can vary from a few cycles per second (hertz) to more than 10^20 hertz. read more