Efficiency Of Machines

Question 1

What of the input energy is always lost or wasted?

Answer 1

Heat

Question 2

The less energy wasted ..

Answer 2

The more efficient the device

Question 3

What is the equation to calculate efficiency?

Answer 3

Useful energy out
Efficiency= ———————-
Total energy in

Question 4

What is the equation for efficiency with power?

Answer 4

Useful power out
Efficiency= ——————–
Total power in

Question 5

Useful devices are only useful because they can transform…

Answer 5

Energy from one form to another.

Question 6

Why do we call it wasted heat?

Answer 6

Because you can do nothing with it

Question 7

Useful energy is…

Answer 7

Concentrated energy

Question 8

As energy is transferred to cooler surroundings the energy becomes….

Answer 8

Less concentrated

Question 9

What do heat exchangers do?

Answer 9

Reduce the amount of heat energy lost

Question 10

How do heat exchangers work?

Answer 10

They pump cool fluid through the escaping heat. The temperature of the heat rises as it gains heat energy. This energy can be converted to useful energy again