Energy Conservation and Efficiency Flashcards
(4 cards)
1
Q
What is the Law of Energy Conservation?
A
Energy cannot be created or destroyed. It can only be transformed into other forms. Total energy stays the same in a system.
Example: Electrical → Light + Heat
2
Q
What is the difference between useful and wasted energy?
A
All energy is transformed, but not all is useful. Useful energy = what we want; Wasted energy = extra forms (like sound or heat).
Example: Hair dryer → Useful: Heat, Wasted: Sound
3
Q
What does energy efficiency tell us?
A
Energy efficiency tells how much useful energy a device gives. More wasted energy = less efficient.
4
Q
What is the efficiency formula?
A
Efficiency = (Useful energy output / Total energy input) × 100%
