When do we say that a pendulum has completed one oscillation?

Two pendulums have time period T and 5T/4. They starts SHM at the same time from the mean position. What will be the phase difference between them after the bigger pendulum completed one oscillation ?

The time taken by the pendulum to complete one oscillation is called______

Two simple pendulum of lengths 1 m and 9 m respectively are both given a displacement in the same direction at the same instant. They will again be in phase after the shorter pendulum has completed number of oscillations are

Two simple pendulums are drawn to same side from their mean position and are released simultaneously. Their time periods are 2 s and 3s. The phase difference between the pendulums when the longer pendulum completes one oscillation is

When do we say that work is done ?

Two simple pendulums of length 0.5 m and 20 m, respectively are given small linear displacement in one direction at the same time. They will again be in the phase when the pendulum of shorter length has completed oscillations.