Question

If the luminous intensity of a 100 W unidirectional bulb is 100 candela, then total luminous flux emitted from the bulb is

• A. 861 lumen
• B. 986 lumen
• C. 1256 lumen
• D. 1561 lumen

Answer 1

Answer: (C)

1256 lumen

Answer 2

$\varphi = 4\pi L = 4 \times 3.14 \times 100$= 1256 lumen.