Ataking the earth revolves round the sun in a circular orbit of `15xx10^(10)` m, with a time period of 1 yr, the time taken by another planet, which is at distance of `540xx10^(10)` m to revolve round the sun in circular orbit once, will be

Options

A. 216 yr
B. 144 yr
C. 72 yr
D. 36 yr

Answer

A

Explanation

`[(T_(1))/(T_(2))]^(2)=[(R_(1))/(R_(2))]^(3)`
`[(1)/(T_(2))]^(2)=[(15xx10^(10))/(540xx10^(10))]^(3)`
`T_(2)=(36)^(3//2)=(6)^(2)=261yr`