Which statement about electromagnetic waves is true?

Which statement about electromagnetic waves is true?

• A. They require matter to transfer energy.
• B. They can travel through empty space.
• C. They cannot travel through a vacuum.
• D. They move energy only when in contact.

Answer: (B)

They can travel through empty space because electromagnetic waves are oscillations of electric and magnetic fields that sustain each other as they propagate. In a vacuum there’s no material medium, yet a changing electric field continually induces a changing magnetic field and vice versa, allowing the wave to move at the speed of light. Energy is carried by the electromagnetic field, so the wave transmits energy through space without any contact with matter. This makes the idea that they require matter false, and the idea that they cannot travel in a vacuum false. Energy transfer isn’t limited to contact with matter; the wave’s energy travels through space on its own.

They can travel through empty space because electromagnetic waves are oscillations of electric and magnetic fields that sustain each other as they propagate. In a vacuum there’s no material medium, yet a changing electric field continually induces a changing magnetic field and vice versa, allowing the wave to move at the speed of light. Energy is carried by the electromagnetic field, so the wave transmits energy through space without any contact with matter. This makes the idea that they require matter false, and the idea that they cannot travel in a vacuum false. Energy transfer isn’t limited to contact with matter; the wave’s energy travels through space on its own.