Time period of pendulum on earth surface is `T_(1)`. Its time period at a height equal to radius of earth is `T_(2)`, then the ratio of `T_(1) : T_(2)` is

Options

A. `8 : 10`
B. `5 : 10`
C. `1 : 1`
D. `2 : 10`

Answer

B

Explanation

`(T_(1))/(T_(2))=sqrt((g_(2))/(g_(1)))=sqrt(((R)/(R+h))^(2))`
`=((R)/(R+R))=(1)/(2)`