Question

Match List-I with List-II:
List-I (Factor):
(A). Luminous Intensity
(B). Luminous Flux
(C). Luminance
(D). Illuminance
List-II (Unit):
(I). Lux (lx)
(II). Candela (cd)
(III). Lumen (lm)
(IV). cd/m2
Choose the correct answer from the options given below:

• A. (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
• B. (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
• C. (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
• D. (A)-(III), (B)-(IV), (C)-(I), (D)-(II)

Hint:

To easily recall:
- Luminous Flux = total light output = Lumens (lm)
- Illuminance = light arriving at a surface = Lux (lx)
- Luminous Intensity = direction-based light = Candela (cd)

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Lighting design in interiors requires a precise understanding of the photometric quantities used to measure light output, direction, and surface brightness.

Step 2: Detailed Explanation:
Let us match the photometric factors in List-I with their standard SI units in List-II:

• (A) Luminous Intensity: Measures the power of light emitted by a source in a particular direction. The unit is the (II) Candela (cd).

• (B) Luminous Flux: The total quantity of visible light emitted by a source per unit time. The unit is the (III) Lumen (lm).

• (C) Luminance: Measures the intensity of light emitted or reflected from a surface per unit area in a given direction (surface brightness). The unit is (IV) Candela per square meter ($\text{cd/m}^2$).

• (D) Illuminance: The total luminous flux incident on a surface per unit area. The unit is the (I) Lux (lx), which equals \(\text{lumens/m}^2\).
This matches the combination: (A)-(II), (B)-(III), (C)-(IV), (D)-(I).

Step 3: Final Answer
The correct matching sequence is (A)-(II), (B)-(III), (C)-(IV), (D)-(I).