Question

A CFL bulb has an efficiency of 8.9% and a power of 22 W. How much light energy does the lightbulb produce in 1 second

Answer 1

The power that the light is able to utilize out of the supply is only 0.089 of the given.
                           Power utilized = (0.089)(22 W)
                                                  = 1.958 W
                                                  = 1.958 J/s
The energy required in this item is the product of the power utilized and the time. That is,
                           Energy = (1.958 J/s)(1 s) = 1.958 J
Thus, the light energy that the bulb is able to produce is approximately 1.958 J. 

Answer 2

On Apex the answer is 1.96J