Question

You are a scientist working on increasing the efficiency of appliances to waste less electricity. You are running experiments measuring the input, output, and waste energy from a new type of light source. Given the data below, determine the percentage of energy transformed into light.
25978.8 joules in, 14153.3 joules wasted, 11825.5 joules out
A. 45.5%
B. 54.5%
C. 11825.5%
D. 83.5%

Answer 1

Answer : Option A) 45.5%
 
Explanation : We use the formula of calculating energy efficiency which is as,

η (in %)= [$P_{Out} / P_{in}$] X 100 
where η is energy efficiency,
and P values are for energy out and in.

So plugging the given values, we get,

η (in %) = (11825.5 / 25978.8) X 100 = 45.5 %