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1. Why do some stars appear blue and some red?
All the stars are and do not have the .
The brightness of a star varies based on its , whereas the colour of the star depends on its .
The hottest stars appear , whereas the coolest stars appear . Our Sun is a even though it looks yellow.
2. How is a satellite maintained in nearly circular orbit?
are designed to revolve in orbit at the height of a few hundred kilometres above the Earth.
The is negligible at this height.
The artificial satellite is carried to the desired height with the help of a . Then, the satellite is released with a so that it is constantly moving in a circular orbit.
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