How devices use waves to send and capture information and energy

Answer Key - Grade 11 Science Worksheet - Building Confidence

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

1. 1.

   A Wi-Fi router sends at 2.4 GHz. With c = 299,792,458 m/s, what is the wavelength, to 0.01 cm, Ari?

   12.49 cm
2. 2.

   A Wi-Fi router sends at 5 GHz. With c = 299,792,458 m/s, what is the wavelength, to 0.01 cm, Bo?

   6 cm

3. Read this first

   Use this

   Signal strip through a phone call:

5. 3.

   In the signal strip, what kind of wave carries the call between the phones, Jun?

   • A radio wave
   • A wave on a wire
   • A sound wave
6. 4.

   In the signal strip, what do the bits 1, 0, 1, 1 stand for, Luz?

   Use the picture in question 3.

   • Part of the voice, as numbers
   • The tower's height
   • The phone's battery charge level
7. 5.

   What kind of wave does an ultrasound scanner use, Milo?

   • X-rays
   • Radio waves
   • Sound waves above hearing
8. 6.

   What carries information along a fiber-optic cable, Noah?

   • Moving water
   • Sound waves
   • Pulses of light
9. 7.

   What does a TV remote usually send to the TV, Pia?

   • Sound waves
   • Infrared light
   • X-rays
10. 8.

    What energy change happens in a solar cell, Ren?

    • Heat to sound
    • Light to electrical
    • Electrical to light
11. 9.

    A cloud moves away and more sunlight reaches a solar panel. What happens to its current, Tala?

    • It stays the same
    • It goes down
    • It goes up
12. 10.

    How does light make a current in a solar cell, Zee?

    • Light heats a wire until it glows
    • Photons free electrons
    • Sunlight pushes the panel