$A$ simple pendulum is vibrating in an evacuated chamber. It will oscillate with:

$A$ simple pendulum of length $1\, m$ is oscillating with an angular frequency $10\, rad/s$. The support of the pendulum starts oscillating up and down with a small angular frequency of $1\, rad/s$ and an amplitude of $10^{-2}\, m$. The relative change in the angular frequency of the pendulum is best given by

Identify the correct statement among the following.

The time period of a simple pendulum is $T$. If its length is increased by $21\%$,what is the percentage increase in its time period?

$A$ simple pendulum of length ' $\ell$ ' has a bob of mass 'm'. It executes $S$.$H$.$M$. of small amplitude '$A$'. The maximum tension in the string is ($g=$ acceleration due to gravity).

$A$ simple pendulum is suspended from the ceiling of a lift. When the lift is at rest,its period is $T$. With what acceleration $a$ should the lift be accelerated upward in order to reduce the period to $\frac{T}{2}$? (Take $g$ as the acceleration due to gravity.)