Question

An LED lightbulb has an efficiency of 11,5% and a power of 10 W. How much
light energy does the lightbulb produce in 1 second?
O A. 1.153
OB. 8.85 J
O C. 103
O D. 3,25 J

Answer 1

The light bulb produces 1.15 J  energy in 1 second.

Explanation:

Efficiency of an electric appliance is defined as the ratio of output power to the input power. In a 100% efficient appliance all of the input power will be converted to output power. In the given question  it is given that

input power= 10W  

efficiency= 11.5%

(output power)/(input power)=efficiency  

output power = input power * efficiency

$=10 \times (11.5/100)=1.15W$

Now we have to calculate the energy produced by the light bulb in 1 second

$energy=power \times time$

$=1.15 \times 1$

=1.15J