Energy Efficiency Flashcards
1
Q
How do you work out the efficiency of an appliance?
A
Useful energy out / total energy in X 100
2
Q
Out of the three energy types : Heat, sound and kinetic is not useful when a car is driven?
A
Heat
Sound
3
Q
If a kettle needs 500 joules to operate it and 50 joules are used for sound , how many Jules are left for heat?
A
450J
4
Q
A speaker uses 600J and uses 60J for sound , how efficient is it?
A
10%
5
Q
Complete the following statement
“energy can be transfered but can’t be…”
A
Destroyed
