Two simple pendulums $A$ and $B$ are made to oscillate simultaneously. It is found that $A$ completes $10$ oscillations in $20 \ s$ and $B$ completes $8$ oscillations in $10 \ s$. The ratio of the lengths of $A$ and $B$ is

Two simple pendulums of equal length cross each other at the mean position. What is their phase difference?

Given below are two statements:
Statement $I :$ $A$ second's pendulum has a time period of $1$ second.
Statement $II :$ It takes precisely one second to move between the two extreme positions.
In the light of the above statements,choose the correct answer from the options given below:

$A$ simple pendulum executing $S.H.M.$ is falling freely along with its support. Then:

$A$ simple pendulum consisting of a ball of mass $m$ tied to a thread of length $l$ is made to swing on a circular arc of angle $\theta$ in a vertical plane. At the end of this arc,another ball of mass $m$ is placed at rest. The momentum transferred to this ball at rest by the swinging ball is

Two simple pendulums of lengths $L_1$ and $L_2$ have time periods $T_1$ and $T_2$ respectively, where $T_1 > T_2$. What is the time period of a simple pendulum of length $(L_1 - L_2)$?