Question

Two planets are revolving around the earth with velocities $v_{1}$ and $v_{2}$ and in radii $r_{1}$ and $r_{2}$ $\left(r_{1} > r_{2}\right)$ respectively. Then :

• A. $v_{1}=v_{2}$
• B. $v_{1} > v_{2}$
• C. $v_{1} < v_{2}$
• D. $\frac{v_{1}}{r_{1}}=\frac{v_{2}}{r_{2}}$

Answer 1

Answer: (B)

$v_{1} > v_{2}$

Answer 2

Orbital velocity $v=\sqrt{g r}$
$\frac{v_{1}}{v_{2}}=\sqrt{\frac{r_{1}}{r_{2}}}$
As, $r_{1} > r_{2}$ so, $v_{1} > v_{2}$.