Which SI base quantity corresponds to the unit 'second'?

• A. Length
• B. Mass
• C. Time
• D. Temperature

Answer: (C)

The unit 'second' is defined as the SI base unit for measuring time. In the International System of Units (SI), time is one of the fundamental quantities, and the second is the standard unit used to quantify its measurement. Each SI base quantity is associated with a specific unit, and time is uniquely linked to the second due to its precise definition, which is based on the vibrations of cesium atoms in atomic clocks.

Understanding the concept of time as a base quantity is essential in various fields of physics and engineering because time plays a critical role in equations of motion, electrical circuits, and many other applications where changes over time are analyzed.