Thank you for reporting, we will resolve it shortly
Q.
The time period of a spy satellite orbiting a few hundred kilometre above the earth's surface $\left(R_{\text {earth }}=6400 \,km \right)$ will approximately be:
Gravitation
Solution:
Speed of a satellite just above earth surface is
$v =\sqrt{g R}=7.9 \,kms ^{-1}, $ and
$T =\frac{2 \pi R}{v}=\frac{2 \pi 6400 \times 100}{7900}$
$=84.79 $ minute
is the time period of satellite revolving very close to earth's surface.
So time period of spy satellite must be slightly greater and so $C$ is the appropriate answer.