Introduction to Electromagnetic Waves and the Electromagnetic Spectrum

What is the speed of electromagnetic waves in a vacuum?

• 3.0 x 10^8 meters per second

• 2.0 x 10^8 meters per second

• 1.5 x 10^8 meters per second

• 4.0 x 10^8 meters per second

Which type of electromagnetic wave is used for satellite communications due to its low absorption by air molecules?

• Ultraviolet rays

• Infrared radiation

• Microwaves

• Radio waves

What is a common use of infrared radiation?

• Medical imaging

• Cooking food

• Fiber optic communications

• Tanning machines

Which part of the electromagnetic spectrum is visible to the human eye?

• Ultraviolet

• Gamma rays

• Infrared

• Visible light

Why should exposure to ultraviolet, X-rays, and gamma rays be limited?

• They are absorbed by water molecules

• They are ionizing and can damage living cells

• They are not visible to the human eye

• They can cause heating