In a simple pendulum experiment, the time in seconds taken for 20 oscillations is noted in 5 trials as `39.2, 38.4, 40.8, 41.4, 40.2`, then the average frequency is ______

Options

A. `0.5 s`
B. `2 s^(-1)`
C. `2 s`
D. `0.5 s^(-1)`

Answer

D

Explanation

Time taken for 20 oscillations
`(39.2 + 38.4 + 40.8 + 41.4 + 40.2)/(5) = (200)/(5) = 40s`
Time taken for one oscillation `= (40)/(20) = 2s`
i.e., Time period 2s
Frequency `= (1)/("Time period") = (1)/(2) = 0.5s^(-1)`