New
New
Year 10
AQA
Higher

Effective insulation

I can explain how to carry out a fair test to investigate insulators.

New
New
Year 10
AQA
Higher

Effective insulation

I can explain how to carry out a fair test to investigate insulators.

Lesson details

Key learning points

  1. In a fair test, only the independent variable is changed so that no other changes could affect the results.
  2. The variables that are deliberately kept the same are called control variables.
  3. A lid on a beaker prevents transfer of energy by convection currents.
  4. Gas is a very poor thermal conductor.

Common misconception

Heat is a substance that flows through an insulator.

Always refer to it being particle vibrations that are passed on through a material and do not refer to heat moving.

Keywords

  • Control experiments - These are done to find a baseline set of results to which others can be compared.

  • Independent variables - These are factors that are changed during an experiment to see how they affect the dependent variable.

  • Dependent variables - These are measured during an experiment to see how they have been affected by changes to the independent variable.

  • Control variables - These are factors that need to be kept constant in an experiment for the test to be fair.

For some groups, it may be appropriate to test the thickness of insulation by adding layers of newspaper and other materials around a drinks can, which is easier to manage than the suggested practical. Digital thermometers give a better resolution, making the cooling pattern easier to see.
Teacher tip

Equipment

Kettles to boil water, beakers with cardboard lids, larger beakers to hold the smaller ones, thermometers, stopwatches and selection of insulating materials.

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Match the following temperatures to their description.
Correct Answer:5600°C,the surface of the Sun

the surface of the Sun

Correct Answer:100°C,boiling point of water

boiling point of water

Correct Answer:0°C,freezing point of water

freezing point of water

Correct Answer:-183°C,boiling point of oxygen

boiling point of oxygen

Correct Answer:20°C,typical room temperature

typical room temperature

Q2.
Which of the following materials is the best thermal insulator?
copper
steel
Correct answer: plastic
iron
aluminium
Q3.
Why is copper a good choice for the base of a frying pan?
An image in a quiz
Correct answer: It is a good thermal conductor and transfers energy quickly.
It is an insulator and so saves energy.
Correct answer: It has a high melting point.
It does not get hot when heated and so the pan can be handled safely.
It conducts electricity.
Q4.
Wool is used in some clothing. Why is wool good at keeping a person warm?
An image in a quiz
Wool produces heat when in contact with the body.
Correct answer: Wool traps air which is a good thermal insulator.
Wool is a good thermal conductor and lets the heat in.
Wool is soft, this makes it comfortable to wear.
Wool has holes that lets the air travel freely through it.
Q5.
Which of the following particles make metals good thermal conductors?
free protons
free neutrons
free ions
Correct answer: free electrons
free molecules
Q6.
What is the condition needed for two objects to be in thermal equilibrium?
One of the objects must be hotter than the other.
One of the objects must be colder than the other.
The two objects must be metals.
The two objects must be thermal conductors.
Correct answer: The objects must be at the same temperature.

6 Questions

Q1.
Match the following key words or phrases to their definitions.
Correct Answer:control experiments,used to find a baseline results to which others can be compared

used to find a baseline results to which others can be compared

Correct Answer:independent variable,its values are selected by the experimenter

its values are selected by the experimenter

Correct Answer:dependent variable,it's values are measured to get a set of results

it's values are measured to get a set of results

Correct Answer:control variables,kept constant in an experiment for the test to be fair

kept constant in an experiment for the test to be fair

Q2.
A thermometer with a resolution of 0.5°C is used in a cooling experiment. What does this resolution mean?
The highest temperature that can be measured is 0.5°C.
The lowest temperature that can be measured is 0.5°C.
Correct answer: The smallest change in temperature that can be measured is 0.5°C.
The temperature will decrease by 0.5°C each second.
The temperature will increase by 0.5°C each second.
Q3.
Why is a cardboard lid used to cover a beaker of water during an experiment to compare insulators?
Correct answer: To reduce energy transfer by convection currents.
To keep the test fair.
To stop the thermometer from falling out.
To prevent energy being transferred to water by radiation.
To control the starting temperature of the water.
Q4.
For a fair test of insulating materials, the ‘amount’ of insulator used should be kept the same for each type. Which of these are ways of controlling the ‘amount’ of insulation used fairly?
keeping the type of the insulation the same
Correct answer: keeping the thickness of the insulation the same
keeping the starting temperature the same
Correct answer: keeping the mass of the insulation the same
keeping the time allowed for cooling the same
Q5.
A pupil tests different insulating materials by insulating a container of hot water and monitoring its temperature over time. How will they conclude which is the best insulator?
the biggest change in temperature in ten minutes
Correct answer: the smallest change in temperature in ten minutes
Correct answer: the smallest fall in temperature each minute
the greatest fall in temperature each minute
Q6.
The temperature of hot water fell by 25°C over 6 minutes with 0 layers of insulation, 15°C with 1 layer, 10°C with 2 layers, and 8°C with 3 layers. What conclusions can be made?
Correct answer: Adding more layers reduces cooling.
Adding more layers has no effect on cooling.
The change in temperature is proportional to the number of layers.
The effectiveness of each additional layer increases.
Correct answer: The effectiveness of each additional layer decreases.

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