Q 11-07-069JEE MainJEE Main 2024 (29 Jan, Shift 2)Easy
A planet takes 200 days to complete one revolution around the Sun. If the distance of the planet from the Sun is reduced to one fourth of the original distance, how many days will it take to complete one revolution?
Answer: (A) 25
By Kepler's third law $T \propto r^{3/2}$:
$$T' = 200\times\left(\frac14\right)^{3/2} = \frac{200}{8} = 25\ \text{days}$$
Solution by Sreeraj P, M.Sc Physics