A student uses a simple pendulum of exactly \(1 \mathrm{~m}\) length to
determine \(\mathrm{g}\), the acceleration due to gravity. He uses a stop watch
with the least count of \(1 \mathrm{sec}\) for this and records 40 seconds for
20 oscillations. For this observation, which of the following statement(s) is
(are) true ?
A) Error \(\Delta \mathrm{T}\) in measuring \(\mathrm{T}\), the time period, is
\(0.05\) seconds
B) Error \(\Delta \mathrm{T}\) in measuring \(\mathrm{T}\), the time period, is 1
second
C) Percentage error in the determination of \(g\) is \(5 \%\)
D) Percentage error in the determination of \(g\) is \(2.5 \%\)