Electromagnetic radiation is made up of

• A. Synchronized oscillation of electric and magnetic fields
• B. Static electric field
• C. Sound waves
• D. Light photons

Answer: (A)

Electromagnetic radiation is a propagating electromagnetic wave, described by changing electric and magnetic fields that reinforce each other. The fields oscillate in sync, with the electric and magnetic components perpendicular to each other and to the direction the wave travels, so energy moves through space via the evolving fields. A static electric field doesn’t travel as a wave, and sound waves are mechanical waves in a medium, not electromagnetic. While light can be described as photons in quantum terms, the classical picture of electromagnetic radiation is precisely these synchronized oscillations of electric and magnetic fields.