Question

Motion of artificial satellite around the earth is powered by:
A) Liquid fuel
B) Solar energy
C) Atomic energy
D) None of these

Answer 1

Hint
A satellite is a moon, planet or man made satellite that revolves around a planet or star. For example, Earth is a satellite because it revolves around the sun. Likewise, the moon is a satellite because it orbits Earth. Earth and the moon are examples of natural satellites. Many artificial, or man-made, satellites orbiting the Earth.

Complete step by step solution
If you have noticed the hint minutely then you can easily answer the question.
The moon is also a satellite, planet or machine. So there is something which helps these things to move around the orbit of the sun or another planet.
Talking about option (A) liquid fuel is not present on the moon but still it moves around the Earth , thus it is not correct.
Seeing options (B) and (C) the same case occurs and thus B and C are also not correct. Then what is the force that binds a body to move around a star or a planet.
A satellite orbits Earth or Sun when its speed is balanced by the pull of that body’s gravity. Without this balance, the satellite would fly in a straight line ( if it has no initial speed ) off into space or fall back to that planet or star.
Artificial Satellites orbit Earth at different heights, different speeds and along different paths. This path is elliptical in shape.
Now it is clear that gravity helps not only artificial satellites but natural satellites too to revolve around the Earth.
Hence option (D) is correct.

Note
Satellites are able to orbit around the planet because they are set into speeds that are fast enough so that they can defend against downward pull of gravity. Satellites do carry their own fuel supply, but unlike how a car uses gas, it is not needed to maintain speed for orbit. It is reserved for changing orbit or avoiding collision with debris.