Length of a simple pendulum I is about 100 cm and is known to have 1 mm accuracy and its period of oscillation is about 2 s. The time of 100 oscillations is measured by a stop watch of least count 0. 1 s. The percentage error in g is

From the given expression of period of oscillation of simple pendulumT=2πl/g⇒T2=4π2l/g⇒g=4π21T2 Here % error in l=1mm100cm×100=0.1100×100=0.1 %And % error inT=0.12×100×100=0.05%% error ing=(% error in 1)+2(% error in T)=0.1+2×0.05=0.2%