Candela is defined as?

• A. Measurement of luminous intensity and the SI base unit of light
• B. A unit of time
• C. A unit of mass
• D. A color measurement

Answer: (A)

Candela measures how bright a light source is in a specific direction. It is one of the SI base units and defines luminous intensity—the perceived brightness of light per solid angle. This makes it the standard unit for brightness in a direction, unlike time, mass, or color measurements, which describe different properties. In formal terms, candela ties directly to the light emitted in a given direction and how that brightness is perceived, establishing its role as the base unit for luminous intensity.