HW 6.4: Electromagnetic (EM) Waves

At what speed do electromagnetic waves travel in a vacuum?

• They all travel at 3 x 10^8 m/s

• It varies depending on the frequency of the wave

• It varies depending on the wavelength of the wave

• It varies depending on the energy of the wave

What happens to electromagnetic waves when they change mediums?

• They become visible

• They travel at a different speed

• They gain energy

• They disappear

When a wave bends or changes direction it is known as

• Diffraction

• Refraction

• Reflection

• Polarization

How are the wavelength and frequency of electromagnetic waves related?

• Not related

• Inversely related (if one goes up, the other one goes down)

• Equal to each other

• Directly proportional (if one goes up, the other one does too)

How much of the spectrum can the human eyes detect (known as visible light)?

• All of it

• Most, but not all of it

• About half of it

• A tiny part of it

Humans perceive different wavelengths of light as different ___________ of light

• brigthness

• colors

• strengths

• speeds

The colors in the visible region of light go from red to violet. ___________ is the region of higher frequency after violet, and __________ is the region of lower frequency than red.

• Gamma rays; radio waves

• Radio waves; gamma rays

• Ultraviolet (UV); infrared

• Infrared; ultraviolet (UV)

Which types of electromagnetic waves are considered ionizing? (this means that they can knock off electrons from atoms, which can cause damage to our cells)

• X-rays, Microwaves, and Radio waves

• Visible light, Infrared, and Ultraviolet

• Infrared, Microwaves, and Radio waves

• Ultraviolet, X-ray, and Gamma rays

Which types of waves are used for communication?

• Radio waves and microwaves

• Infrared and ultraviolet (UV)

• Radio waves and x-rays

• X-rays and gamma rays

What happens to EM waves when they interact with matter?

• They are reflected

• They are absorbed

• They are transmitted (go through)

• Any combination of the other three