Give reasons for the following – State, in brief, how artificial satellites are used in transmitting television programmes over large distances.
Artificial satellites are man-made objects which can be made to revolve around the earth. These satellites stay in the same position relative to the surface of the earth; hence the broadcasting station does not lose contact with the receiver.
A satellite receives a microwave signal from a ground station on the earth. Its amplifiers first amplify it. Thereafter, its transmitters re-transmit the (amplified) signal back to a receiving station on earth at a different frequency. This is how artificial satellites are used in transmitting television programmes over large distances.