Question

Assertion: A satellite moving in a circular orbit around the earth has a total energy $E_{0}$, then its potential energy is $-E_{0}$.
Reason: Potential energy of the body at a point in a gravitational field of orbit is $\frac{-G M m}{R}$.

• A. If both the assertion and reason are true and reason explains the assertion.
• B. If both the assertion and reason are true but reason does not explain the assertion.
• C. If assertion is true but reason is false.
• D. If assertion is false but reason is true.

Answer 1

Answer: (D)

Here assertion is false but reason is true For satellite.
$KE = \frac{GMm}{2R}$
and $PE = \frac{-GMm}{R}$
Total energy, $E_0 = KE + PE$
$= \frac{GMm}{2R} - \frac{GMm}{R}$
$= \frac{-GMm}{2R} = \frac{PE}{2}$
$PE = 2E_0$