Two simple pendulums of length 1 m and 16m respectively are both given small displacement in the same direction at the same instant. They will be again in phase after the shorter pendulum has completed n oscillations. The value of n is :
\[ T = 2\pi\sqrt{\frac{l}{g}} \]
\[ T_{1}= 2\pi\sqrt{\frac{1}{g}}= 2 sec \]
\[ T_{2}= 2\pi\sqrt{\frac{16}{g}}= 8 sec \]
