A communications satellite in orbit sends a parallel beam of signals down to earth. If these signals obey the same laws of reflection as light and are to be focussed onto a small receiving aerial, what should be the best shape of the metal 'dish' used to collect them?
Download our app for free and get startedPlay store
A communications satellite sends a parallel beam of signals down to the Earth. If these signals are to be focussed onto a small receiving aerial, then the best shape of the metal dish that can be used to collect them would be concave. The metal dish will behave like a concave mirror, which is a converging mirror.
art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    Refractive index of diamond with respect to glass is 1.6 and absolute refractive index of glass is 1.5. Find out the absolute refractive index of diamond.
    View Solution
  • 2
    The diagrams show the appearance of a fork when placed in front of and close to two mirrors A and B, turn by turn.
    1. Which mirror is convex.
    2. Which mirror is concave.
    Give reasons for your choice.
    View Solution
  • 3
    List some things that convex lens and concave mirror have in common.
    View Solution
  • 4
    If the object is moved further away from the mirror, what changes are there in the position and size of the image?
    View Solution
  • 5
    Draw ray diagrams showing the image formation by a convex lens when an object is placed:
    Between optical centre and focus of the lens.
    View Solution
  • 6
    The refractive indices of three media are given below :
    MediumRefractive Index
    A1.6
    B1.8
    C1.5
    A ray of light is travelling from $A$ to $B$ and another ray is travelling from $B$ to $C$.
    (a) In which of the two cases the refracted ray bends towards the normal?
    (b) In which case does the speed of light increase in the second medium?
    Give reasons for your answer.
    View Solution
  • 7
    The velocity of light in water is $\frac{3}{4}$ times the velocity of light in vacuum. Find the refractive index of water.
    View Solution
  • 8
    What is the magnification produced by a rear view mirror fitted in vehicles?
    View Solution
  • 9
    An extended object in the form of an arrow pointing upward has been placed in front of plane mirror. Draw a labelled ray-diagram to show the formation of its image.
    View Solution
  • 10
    List two properties of the images formed by convex mirrors. Draw ray diagram in support of your answer.
    View Solution