How devices use waves to send and capture information and energy
Grade 11 Science Worksheet
Circle the best answer, or write your answer on the line.
An ultrasound pulse returns from a boundary in a gel test block after 130 μs. The scanner assumes 1540 m/s. How deep is the boundary, to 0.01 cm, Ari?
An ultrasound pulse returns from a boundary in a gel test block after 78 μs. The scanner assumes 1540 m/s. How deep is the boundary, to 0.01 cm, Bo?
An ultrasound pulse returns from a boundary in a gel test block after 200 μs. The scanner assumes 1540 m/s. How deep is the boundary, to 0.01 cm, Esme?
The scanner assumes sound travels 1540 m/s. In the signal strip, why does the scanner halve each echo time, Luz?
- Half the echo is lost
- Sound slows down by half in the gel
- The pulse goes down and back
Panels are rated at 1000 W/m² of sunlight (NREL test conditions). A 1.6 m² panel is 20% efficient. What power does it give, Milo?
- 320 W
- 200 W
- 1600 W
A second panel has twice the area and the same efficiency. How does its power compare, Noah?
- Four times as much
- Half as much
- Twice as much
A panel is 20% efficient. What does that mean, Pia?
- It works 20% of the day
- It lasts 20 years
- It turns 20% of the light into electricity
Why do phones use radio waves rather than visible light to reach a tower, Ren?
- Radio is faster than light
- Light can't carry bits
- Radio passes through walls
Why do different radio stations and phones use different frequencies, Tala?
- So some travel faster
- So their signals don't mix
- So they use less battery
Why does a digital call stay clear even with a little noise, Zee?
- The phone turns the noise up
- Noise can't reach radio waves
- Bits are read as 0 or 1