What SI unit represents luminous intensity?

The SI unit that represents luminous intensity is the candela, often abbreviated as "cd." Luminous intensity is a measure of how much light is emitted by a source in a particular direction and is an important concept in fields such as lighting, photography, and vision science. One candela is defined as the luminous intensity of a source that emits monochromatic radiation at a frequency of 540 terahertz and has a radiant intensity of 1/683 watt per steradian. This makes the candela a crucial unit for quantifying the perception of brightness in human vision, allowing for comparisons among various light sources.

In contrast, the other units listed are used for different physical quantities: the mole (mol) measures the amount of substance, the kilogram (kg) measures mass, and the meter (m) measures length. Each of these units serves specific purposes within the International System of Units (SI), and they do not pertain to the measurement of luminous intensity. Therefore, understanding the role of the candela helps clarify the context of how various light sources can be evaluated for their intensity in relation to human perception.