Question

The least count of a stop watch is 0.2 s, The time of 20 oscillations of a pendulum is measured to be 25s. The percentage error in the time period is
A. `16%`
B. `0.8%`
C. `1.8%`
D. `8%`

Answer 1

`Deltat = 0.2 s`
`t =25s`
`T = (t)/(N) rArr (DeltaT)/(T) = (Deltat)/(t) = (0.2)/(25) = 0.8%` .