9I End of Unit Test

9I End of Unit Test

Name ______Class ______

1 Write the type of energy underneath each picture. The words you need are in the box.

chemical kinetic light strain

A blown up balloon. / A packet of crisps. / A lit candle. / A moving car.
______/ ______/ ______/ ______

[2 marks]

2 Fill in the gaps on this energy flow diagram.

[3 marks]

3 A car engine uses chemical energy, and changes it to other forms of energy.

a Where is the chemical energy stored? ______

[1 mark]

b Name three kinds of energy that a car engine produces.

______

[2 marks]

c Which form of energy is useful energy? ______

[1 mark]

4 A light bulb changes electrical energy to heat and light energy. If you could measure all the heat and light energy produced, how much energy would there be compared to the electrical energy it used?

more electrical energy than heat and light energy

the same amount of electrical energy as heat and light energy

less electrical energy than heat and light energy

[1 mark]

5 Write a sentence to describe what voltage is.

______

[1 mark]

6
/ a Add a voltmeter to this circuit to measure the voltage across the bulb.
[2 marks]
b The cell supplies 6 V, and the voltage across the bulb is 2 V. What is the voltage across the resistor?
______
______

[1 mark]

7 Homes can be heated by burning gas in a boiler or fire. Boilers are about 80% efficient. Electric fires or storage heaters can also be used, which are about 95% efficient.

a What does energy efficiency mean?

______

[1 mark]

b What percentage of the energy does a gas boiler waste? ______

[1 mark]

c How is this energy wasted? ______

[1 mark]

d If 1500 J of energy is supplied to a gas boiler, how much useful heat energy does it release?

______

[1 mark]

e Using a gas boiler is more energy efficient overall than using electric fires.

Explain why this is so.

______

[2 marks]

8 A /

The book in drawing A has 5 J of energy because it is on the shelf.

a What two types of energy does the book have in drawing B?

______

[2 marks]

b i In drawing C, the book has lost this 5 J of energy. In what form is this 5 J of energy now?

______

[2 marks]

ii Why isn’t this energy useful any more?

______

[1 mark]