By the time, the bigger pendulum makes one full oscillation, the smaller pendulum will make $\left( {1 + \frac{1}{4}} \right)$ oscillation. The bigger pendulum will be in the mean position and the smaller one will be in the positive extreme position. Thus, phase difference $= 90°$

where $x=$ displacement at time $t$
$\omega =$ frequency of oscillation
Which one of the following graphs shows correctly the variation $a$ with $t$ ?
Here $a=$ acceleration at time $t$
$T=$ time period
