Satellites - Orbital Velocity & Period question from NEET 1993 (AIPMT)

Answer: (d)

1. Kepler's third law: $T \propto r^{3/2}$, independent of the satellite's mass.
2. Taking orbit radii $r$ and $2r$ (from the earth's centre): $\frac{T_A}{T_B} = \left(\frac{r}{2r}\right)^{3/2} = \frac{1}{2\sqrt{2}}$
3. So the answer is (d) $1:2\sqrt{2}$.