Assertion: if an earth satellite moves to a lower orbit, there is some dissipation of energy but the satellite speed increases.
Reason: The speed of satellite is a constant quantity.

Options

A. If both the assertion and reason are true and reason is a true explantion of the assertion.
B. If both the assertion and reason are true but the reason is not true the correct explantion of the assertion.
C. If the assertion is true but reason false
D. If both the assertion and reason are false.

Answer

C

Explanation

Due to resistance force fo atmosphere, the satellite revolving around the earth losses kinetic energy. Therefore, in a particular orbit the gravitational attraction of earth on satellite becomes greater than that required for cicular orbit there. therefore, satellite moves down to a lower orbit. In the lower orbit as the potential energy `(U=-GMm//r)` becomes more negative, hence kinetic energy `(E_(K)=GMm//2r)` increases, and hence speed of satellite increases.