Asked by archi
A satellite dish is designed to pick up radio waves from geostationary satellites about 36000 km about the Earth's surface.
If the dish's surface is a part of a sphere of radius R, where should the receiver be placed compared to the center of the dish?
1. At a distance R/2 from the center of the dish, behind the dish (on the convex side).
2. At the center of the sphere, a distance R from the dish.
3. At a distance R/2 from the center of the dish, in front of the dish (on the concave side).
4. At a distance R behind the dish.
If the dish's surface is a part of a sphere of radius R, where should the receiver be placed compared to the center of the dish?
1. At a distance R/2 from the center of the dish, behind the dish (on the convex side).
2. At the center of the sphere, a distance R from the dish.
3. At a distance R/2 from the center of the dish, in front of the dish (on the concave side).
4. At a distance R behind the dish.
Answers
Answered by
drwls
The satellte dish reflects the signal from the satellite to a detector in front of the concave side, at the focal point. It acts just like a mirror for light.
You should know the forcal point of a mirror is at R/2.
DirecTV satellite dishes are off-axis paraboloids, not part of a sphere. The focal point and detectors are thus kept out of the way of the incoming beam.
You should know the forcal point of a mirror is at R/2.
DirecTV satellite dishes are off-axis paraboloids, not part of a sphere. The focal point and detectors are thus kept out of the way of the incoming beam.
There are no AI answers yet. The ability to request AI answers is coming soon!
Submit Your Answer
We prioritize human answers over AI answers.
If you are human, and you can answer this question, please submit your answer.