Which of the following are not correct?
The time period of a given pendulum is not constant.

Explanation

To determine whether the statement "The time period of a given pendulum is not constant" is correct or incorrect, we can analyze the concept of the time period of a pendulum step by step.

### Step-by-Step Solution:

1. **Understanding the Pendulum**: A pendulum consists of a weight (or bob) attached to a string or rod that swings back and forth under the influence of gravity.

2. **Time Period Definition**: The time period (T) of a pendulum is the time it takes to complete one full swing (from one side to the other and back again).

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