The period of a planet around sun is 27 times that of earth the ratio of radius of planet orbit to the radius of earth's orbit is

Options

A. 4
B. 9
C. 64
D. 27

Answer

B

Explanation

From kepler 's third law of planetary motion `T^(2) prop R^(3)`
Given `T_(p)=27 T_(e ),(T_(e )^(2))/(T_(p)^(2))=(R_(e )^(3))/(R_(p)^(3))`
`rarr R_(p)=9R_(e )`