Physics - Energy efficiency

How do you calculate energy efficiency?
Useful energy output/ total energy input
1 of 5
A hob is heating water in pan. 15KJ of thermal energy is transferred by a hob. 12KJ passes into water. Calculate efficiency
12/15 =0.8 = 80%
2 of 5
How could you increase efficiency?
Add lid so less energy is transferred
3 of 5
Electric current deliverers 60 watts to bulb. 3 watts are transferred as light. Calculate efficiency
3/60 = 0.05 = 5%
4 of 5
.
.
5 of 5

Other cards in this set

Card 2

Front

A hob is heating water in pan. 15KJ of thermal energy is transferred by a hob. 12KJ passes into water. Calculate efficiency

Back

12/15 =0.8 = 80%

Card 3

Front

How could you increase efficiency?

Back

Preview of the front of card 3

Card 4

Front

Electric current deliverers 60 watts to bulb. 3 watts are transferred as light. Calculate efficiency

Back

Preview of the front of card 4

Card 5

Front

.

Back

Preview of the front of card 5

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Energy resources »