A simple pendulum completes 10 oscillation in 30 second. Another simple pendulum takes 40 seconds to complete 10 oscillations at the same place. The ratio of the lengths of the simple pendulums is

Options

A. `(5)/(16)`
B. `(9)/(16)`
C. `(3)/(16)`
D. `(13)/(16)`

Answer

B

Explanation

`(T_(1))/(T_(2))=sqrt((l_(1))/(l_(2))) therefore (l_(1))/(l_(2))=(T_(1)^(2))/(T_(2)^(2))=(9)/(16)`