How devices use waves to send and capture information and energy

Answer Key - Grade 11 Science Worksheet - Challenge Me

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

1. 1.

   Quartz glass has n = 1.46 (Engineering ToolBox). For light inside it meeting air (n = 1.00), what is the critical angle, to 0.01°, Ari?

   43.23 °
2. 2.

   Water has n = 1.333 (Engineering ToolBox). For light inside it meeting air (n = 1.00), what is the critical angle, to 0.01°, Bo?

   48.61 °
3. 3.

   Diamond has n = 2.417 (Engineering ToolBox). For light inside it meeting air (n = 1.00), what is the critical angle, to 0.01°, Esme?

   24.44 °
4. 4.

   Why does light stay inside a fiber-optic cable as it bends, Jun?

   • The glass soaks up the light and glows
   • Total internal reflection at the edge
   • The light slows to a stop
5. 5.

   How must the cladding around a fiber's core compare with the core, Kira?

   • It has a higher refractive index
   • It must be made of metal
   • It has a lower refractive index
6. 6.

   A fiber is bent so sharply that light meets the edge at less than the critical angle. What happens, Luz?

   • The light speeds up
   • More light is trapped
   • Some light escapes
7. 7.

   Why do ultrasound scanners use millions of vibrations per second, Milo?

   • High pitches are louder
   • Low pitches can't enter gel
   • Short waves show fine detail
8. 8.

   A router offers 2.4 GHz and 5 GHz. Which usually reaches farther through walls, Pia?

   • Both reach equally far
   • 2.4 GHz, with its longer waves
   • 5 GHz, since it is faster
9. 9.

   Ren says ultrasound scanners use X-rays. Agree or disagree?

   • Agree: they use very weak X-rays
   • Agree: echoes are X-rays
   • Disagree: they use sound waves
10. 10.

    Tala says a solar panel turns all the sunlight it gets into electricity. Agree or disagree?

    • Disagree: much becomes heat
    • Agree: sunlight is pure electricity
    • Agree: panels waste no energy