Q. 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 $lumen$
Explanation
(c) $\phi = 4\pi L = 4 \times 3.14 \times 100 = 1256\ lumen$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.