Question

In the above problem the luminous efficiency of the bulb in lumen/watt will be

• A. $4\pi$
• B. $37\pi$
• C. $2\pi$
• D. $\pi$

Answer 1

The correct option is A $4\pi$

We have total luminous flux,
$L=4\pi I$
Luminous efficiency of the bulb in lumen/watt will be $4\pi$.