Question

The old unit of the luminosity of light is

• A. Watt
• B. candle power
• C. lumen
• D. both (A) and (C)

Answer 1

The correct option is B

candle power

Explanation of correct option:

Option B:

1. The luminosity of light is the measure of radiated light.
2. The old unit of luminosity is candle power.

Explanation of incorrect option:

1. Option A: Watt: Watt is the SI unit of power.
2. Option C: Lumen: Lumen is the SI unit of the luminosity of light. It is a modern unit of the luminosity of light.

The correct option is B: candle power