Worksheet

The electromagnetic spectrum and its uses

Grade 11 Science Worksheet - Building Confidence

NameDate

Circle the best answer, or write your answer on the line.

  1. Bo's phone uses a signal at 1.5 GHz. What is the wavelength of the signal?

  2. Which list orders these waves from lowest to highest photon energy: UV, radio, X-rays, infrared, visible, Jun?

    • X-rays, UV, visible, infrared, radio
    • Infrared, radio, visible, X-rays, UV
    • Radio, infrared, visible, UV, X-rays
    • Radio, visible, infrared, UV, X-rays

  3. Green light is 550 nm and red light is 700 nm. Which has the higher frequency, and about what is it, Kira?

    • Both the same, since light has one speed
    • Red, about 4.3 × 10¹⁴ Hz, since longer waves have higher frequency
    • Green, about 5.5 × 10¹⁴ Hz
    • Green, about 5.5 × 10¹¹ Hz

  4. The microwave band runs from about 1 mm to 30 cm. Where does a 12 cm wave fall, and what is its frequency, Luz?

    • Inside the microwave band, at about 36 MHz
    • In the radio band, since 12 cm is longer than 1 mm
    • Inside the microwave band, at about 2.5 MHz
    • Inside the microwave band, at about 2.5 GHz

  5. Why can X-rays show a broken bone through skin when visible light cannot, Milo?

    • Bones glow when X-rays hit them, lighting the picture
    • X-rays travel faster than visible light through skin
    • X-ray photons pass through soft tissue; bone absorbs them
    • X-rays are brighter than visible light, so they show more

  6. Why can ultraviolet sunburn skin when visible light of the same brightness does not, Noah?

    • Each UV photon carries more energy, enough to damage skin cells
    • UV travels faster than visible light, so it hits harder
    • UV has longer wavelengths, so each photon carries more energy
    • UV is a hotter kind of light than visible light is

  7. Why can Wi-Fi pass through a wall, but a TV remote's infrared cannot, Pia?

    • Radio waves travel faster than infrared, so they get through
    • Walls let 12 cm radio waves through but block infrared
    • Wi-Fi has more energy per photon than infrared
    • Infrared is too bright to pass through a wall

  8. A radio signal and a flash of light leave the Moon together, 384,400 km away. Which arrives first, Ren?

    • They arrive together, after about 1.3 s
    • The light, since its frequency is higher
    • The radio signal, since its wavelength is longer
    • They arrive together, after about 1.3 minutes

  9. In a vacuum, a wave's frequency doubles. What happens to its wavelength, Tala?

    • It quadruples, because λ goes as f²
    • It doubles, because the wave speeds up
    • It halves, because the speed stays fixed
    • It stays the same, because it is the same kind of wave

  10. Wi-Fi works at 2.4 GHz and at 5 GHz. Which has the longer wavelength, and by about how much, Zee?

    • 5 GHz, by a factor of about 2
    • Neither: they both travel at c
    • 2.4 GHz, by a factor of about 2.4
    • 2.4 GHz, by a factor of about 2
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The electromagnetic spectrum and its uses

Answer Key - Grade 11 Science Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

  1. Bo's phone uses a signal at 1.5 GHz. What is the wavelength of the signal?

    0.2 m

  2. Which list orders these waves from lowest to highest photon energy: UV, radio, X-rays, infrared, visible, Jun?

    • X-rays, UV, visible, infrared, radio
    • Infrared, radio, visible, X-rays, UV
    • Radio, infrared, visible, UV, X-rays
    • Radio, visible, infrared, UV, X-rays

  3. Green light is 550 nm and red light is 700 nm. Which has the higher frequency, and about what is it, Kira?

    • Both the same, since light has one speed
    • Red, about 4.3 × 10¹⁴ Hz, since longer waves have higher frequency
    • Green, about 5.5 × 10¹⁴ Hz
    • Green, about 5.5 × 10¹¹ Hz

  4. The microwave band runs from about 1 mm to 30 cm. Where does a 12 cm wave fall, and what is its frequency, Luz?

    • Inside the microwave band, at about 36 MHz
    • In the radio band, since 12 cm is longer than 1 mm
    • Inside the microwave band, at about 2.5 MHz
    • Inside the microwave band, at about 2.5 GHz

  5. Why can X-rays show a broken bone through skin when visible light cannot, Milo?

    • Bones glow when X-rays hit them, lighting the picture
    • X-rays travel faster than visible light through skin
    • X-ray photons pass through soft tissue; bone absorbs them
    • X-rays are brighter than visible light, so they show more

  6. Why can ultraviolet sunburn skin when visible light of the same brightness does not, Noah?

    • Each UV photon carries more energy, enough to damage skin cells
    • UV travels faster than visible light, so it hits harder
    • UV has longer wavelengths, so each photon carries more energy
    • UV is a hotter kind of light than visible light is

  7. Why can Wi-Fi pass through a wall, but a TV remote's infrared cannot, Pia?

    • Radio waves travel faster than infrared, so they get through
    • Walls let 12 cm radio waves through but block infrared
    • Wi-Fi has more energy per photon than infrared
    • Infrared is too bright to pass through a wall

  8. A radio signal and a flash of light leave the Moon together, 384,400 km away. Which arrives first, Ren?

    • They arrive together, after about 1.3 s
    • The light, since its frequency is higher
    • The radio signal, since its wavelength is longer
    • They arrive together, after about 1.3 minutes

  9. In a vacuum, a wave's frequency doubles. What happens to its wavelength, Tala?

    • It quadruples, because λ goes as f²
    • It doubles, because the wave speeds up
    • It halves, because the speed stays fixed
    • It stays the same, because it is the same kind of wave

  10. Wi-Fi works at 2.4 GHz and at 5 GHz. Which has the longer wavelength, and by about how much, Zee?

    • 5 GHz, by a factor of about 2
    • Neither: they both travel at c
    • 2.4 GHz, by a factor of about 2.4
    • 2.4 GHz, by a factor of about 2