Savitha, a XI standard student, while conducting an experiment to determine the effective length of a simple pendulum L, notes down the data of time…

Savitha, a XI standard student, while conducting an experiment to determine the effective length of a simple pendulum L, notes down the data of time taken to complete $\displaystyle 30$ oscillations as $\displaystyle 60$ s and hence calculates the length of the simple pendulum as : (Take $\displaystyle \pi^2=9.8$, and $\displaystyle \mathrm{g}=9.8 \mathrm{~m} / \mathrm{s}^2$ )