Question

According to kepler's laws of planetary motion
[Symbols have their usual meaning]

• A.
  $T\propto R$
• B.
  $T\propto R^{1/2}$
• C.
  $T\propto R^{3/2}$
• D.
  $T\propto R^{2/3}$
  

Answer 1

The correct option is C

$T\propto R^{3/2}$
According to kepler’s third law of planetary motion,$T^2\propto R^3$
$\Rightarrow T\propto R^{3/2}$

Here, T is the time period of revolution of the planet and R is the length of the semi-major axis of the elliptical planetary path.

Hence, the correct answer is option (c).