Unit 7 Review

All electromagnetic waves travel at the same speed in a vacuum. However, different kinds of electromagnetic waves have different wavelengths. For example, microwaves have longer wavelengths than visible light. How is it possible for both microwaves and visible light to travel at the same speed in a vacuum if they have different wavelengths?

• Microwaves and visible light have the same energy.

• Microwaves and visible light have different frequencies.

• The waves of visible light have less energy than microwaves.

• The distance between a point on one wave to the identical point on the next wave is the same for both microwaves and visible light.

The graph below compares the waves that are part of the electromagnetic spectrum. What can you conclude about gamma rays from the data shown in this graph?

• Gamma rays have the longest wavelength.

• Gamma rays have the narrowest range of wavelengths.

• Gamma rays and X-rays may have the same wavelength.

• Gamma rays and radio waves have the same wavelength.

Felipe was enjoying the sunny day at the beach. He told his friend Carl that he was really enjoying the warm feeling that he was getting as he sat in the Sun. Carl explained that the electromagnetic radiation was responsible for this warm feeling. Which part of the electromagnetic spectrum was responsible for making Felipe feel warm?

• gamma rays

• microwaves

• visible light

• infrared waves

The graphs below show the wavelengths of four types of electromagnetic waves. Which graph most likely illustrates radio waves?

• A

• B

• C

• D

Visible light consists of electromagnetic waves that humans can see. Which color of visible light has the lowest frequency?

• blue

• red

• violet

• yellow

The diagram below represents waves from the electromagnetic spectrum. Assume that the diagram above shows infrared radiation. How would a diagram showing X-rays be different?

• The distance indicated by D would be longer.

• The distance indicated by C would be shorter.

• The point represented by A would not be present.

• The point represented by B would be at the top of each wave.

Both radio and television signals are carried by radio waves. What other type of electromagnetic radiation is used to send information over long distances?

• X-rays

• microwaves

• gamma rays

• ultraviolet light

Infrared and ultraviolet light are both part of the electromagnetic spectrum. How is infrared light different from ultraviolet light?

• Only ultraviolet light comes from the Sun.

• Only ultraviolet light travels at the speed of light.

• Infrared light has a higher frequency than ultraviolet light.

• Infrared light has longer wavelengths than ultraviolet light.

As Miguel walked farther from the soccer field after the evening game, the lights from the field got dimmer. What causes a beam of light to get dimmer the farther it travels through the air?

• absorption

• reflection

• refraction

• scattering

The diagram below shows what happens when light strikes a material. Which behavior of light is NOT shown in this diagram?

• absorption

• reflection

• refraction

• transmission