Free Printable Sankey Diagrams and Energy Efficiency

1.

A kettle uses 100J of electrical energy to produce 7J of sound energy and 93J of thermal energy. How efficient is the kettle?

a)

100%

b)

7%

c)

93%

d)

95%

2.

A washing machine uses 250J of electrical energy to produce 125J of useful energy. How efficient is it?

a)

5%

b)

50%

c)

55%

d)

100%

3.

A hairdryer uses 300J of energy to produce 60J of sound energy and 240J of thermal energy. Calculate it's efficiency.

a)

80%

b)

90%

c)

20%

d)

100%

4.

An iPhone charger coverts 75J of electricty in to 50J of charge and 25J of thermal energy. How efficient is the charger?

a)

10%

b)

100%

c)

33%

d)

67%

5.

What type of device might this Sankey be about?

a)

A very efficient LED light bulb

b)

A very inefficient incandescent light bulb

c)

A coal power plant

d)

A wind turbine

6.

If this household wanted to use less energy, where should they first focus their efforts.

a)

Water heater

b)

Better lighting

c)

Unplugging electronics

d)

More efficient air conditioning

7.

The law of energy conservation says the total energy before the change _______ the total energy after it

a)

is less than

b)

is more than

c)

affects

d)

equals

8.

Efficiency is calculated by useful energy output divided by total energy input, expressed as a percentage

a)

False

b)

True

9.

What is an energy transfer?

a)

Dancing

b)

Movement of energy

c)

Movement of energy from one store to another

d)

something moving

10.

In energy transformations, "wasted energy" usually takes what form?

a)

heat

b)

chemical energy

c)

light

d)

sound waves

11.

Which of these equations is correct?

a)

$efficiency\ =\ \frac{useful\ energy\ transferred}{total\ energy\ transferred}$

b)

$efficiency\ =\ \frac{total\ energy\ transferred}{useful\ energy\ transferred}$

c)

$energy\ =\ efficiency\ \times100\%$

d)

$efficiency\ =\ \frac{wasted\ energy\ transferred}{total\ energy\ tranferred}$

12.

No machine in existence has 100% efficiency due to ____________________.

a)

magic

b)

friction

c)

smoke

d)

input

13.

A (a) diagram shows the energy transfers in a system.

14.

Almost all objects lose energy in the form of (a) .

15.

Which bulb is the most efficient?

a)

Filament bulb

b)

LED light

c)

CFL lamp

Sankey Diagrams and Energy Efficiency

Total questions: 15

Worksheet time: 13mins

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