Question

Which of the following is correct about the time period of a pendulum, whose length (length of thread) is 2 m and mass of whose bob (metallic ball) is 2 kg, when it is set in motion?

Answer 1

Answer:

The time period of a simple pendulum is the time taken by the pendulum to complete one oscillation which remains constant. However, it can be changed by changing the length of the pendulum.

Answer 2

The time period of the pendulum is always constant (A).

Given:

Length of the thread $=2m$

Mass of the bob $=2kg$

To find:
The correct option among the given following options.

Solution:
We know, the time period of an oscillating pendulum is given by

$T=2\pi \sqrt{\frac{l}{g} }$

We have, $l=2m$  $;$ $g=10m/s^{2}$

$T=2(3.14) \sqrt{\frac{2}{10} }$

$T=2.8$ $sec$

Hence, the time period of the oscillation of the pendulum is 2.8 sec.

From the equation of the time period of the pendulum, we can see that, time period of the pendulum is directly proportional to the length of the thread and inversely proportional to the acceleration due to gravity.

Since, acceleration due to gravity is a constant quantity hence, it does not change with passage of time.

Therefore, the time period is only directly proportional to the length of the string.

                                      $T$ ∝ $\sqrt{l}$

Since, we have been given that the length of the string is not changing hence, the time period of the pendulum is always constant.

Final answer:

Hence, the time period of the pendulum is always constant (A).

Although your question is incomplete, you might be referring to the question below.

Which of the following is correct about the time period of a pendulum, whose length (length of thread) is 2 m and mass of whose bob (metallic ball) is 2 kg, when it is in motion.

1. Is always constant.
2. Increases slowly.
3. Decreases slowly.
4. First increases then decreases.