Energy Efficiency Flashcards
1
Q
what is the formula for energy efficiency?
A
useful energy output / total energy input
2
Q
300J has been inputted into 2 lamps. Lamp 1 has 45J of light. Lamp 2 has 225J of light. how many more times efficient is lamp 2?
A
Lamp 1 = 45/300 = 0.15
Lamp 2 = 225/300 = 0.75
0.75/0.15 = 5x more efficient
3
Q
a microwave is 70% efficient. total energy input is 800W. calculate the useful energy output
A
UEO / TEI = E
xTEI
UEO = E x TEI
= 70 / 100 = 0.7
= 0.7 x 800 = 560W
