Efficiency Flashcards
1
Q
What is efficiency?
A
- Amount of useful energy
2
Q
When are useful devices useful?
A
- They transfer energy from one store to another
3
Q
When is input energy wasted?
A
- Transferred to a useless energy store
- Thermal energy store
4
Q
Formulae for efficiency:
A
Useful output energy transfer / Total input energy transfer
Useful power output / Total power input
5
Q
Why is any device 100% efficient?
A
- They’ll always be energy transferred to useless store
6
Q
What device is 100% efficient and why?
A
- Electric heaters
- All energy in electrostatic energy store transferred to “useful” thermal energy store
