Electrical Engineering XYZ MCQs

SI unit of length is:

- feet
- meter
- inch
- centimeter

Correct answer: 2. meter

Explanation: The SI unit of length is the **meter**.

Here is a breakdown of the correct answer and why the other options do not fit:

**Meter**: The meter is the base unit of length in the International System of Units (SI). It is defined by the International Bureau of Weights and Measures (BIPM) as the length of the path traveled by light in a vacuum in 1/299,792,458 of a second. This definition establishes the meter based on a fundamental constant of nature (the speed of light), making it a very precise standard for measuring length.**Feet**: This is a unit of length but not part of the SI system. It is commonly used in the United States and a few other countries that utilize the imperial system. One foot equals 0.3048 meters.**Inch**: Like the foot, the inch is also part of the imperial measurement system and is not an SI unit. One inch is defined as exactly 25.4 millimeters, which are part of the metric system but not the base unit for length.**Centimeter**: Although the centimeter is a unit of length within the metric system, it is not the SI base unit. It is, however, derived from the meter (1 centimeter equals 0.01 meters) and is commonly used, but for SI purposes, the base unit is the meter.

Therefore, the correct answer to the MCQ is **Meter**.