contestada

A 4.0 W LED bulb produces 240 lumens. What is the efficacy of the bulb?
1. 1.7 lm/W
2. 60 lm/W
3. 236 lm/W
4. 244 lm/W

Respuesta :

Efficacy is the ratio of light output from a lamp or a bulb to the electric power it consumes and is measured in lumens per watt (LPW).
In this case; the power is 4 watt and the number of lumens is 240.
Efficacy = lumens/power
            = 240/4
            = 60 lm/W
Thus the efficacy of the bulb is 60 lm/W

Answer:

its B) 60

Explanation: