Primary 6 · Science · Process Skills: Fair Test & Variables
Process Skills: Fair Test & Variables questions for Primary 6 Science
10 questions to work through online, 2 of them written out the way the paper asks. Answer and you get the working straight away, then a score at the end. No sign-up, and you can retake it as often as you like.
- Choosing set-ups for an aim
- Purpose of a set-up
- What a conclusion may say
- Predicting beyond the data
- Spotting the hidden variable
- Improving an experiment
- Reading a results table
- Naming the set-up
- Naming what must not change
- Designing from scratch
| Set-up | Insulation | Lid | Temperature after 30 min (°C) |
|---|---|---|---|
| W | ✓ | ✓ | 68 |
| X | ✓ | ✗ | 54 |
| Y | ✗ | ✓ | 49 |
| Z | ✗ | ✗ | 38 |
Answers and explanations for all 10 questions
Every answer with the reasoning behind it. Worth reading after you have tried the set — or on its own, if you are a parent marking it.
Which two set-ups shown above should be compared to find out whether the colour of light affects growth at 30 °C?
Answer: C and D
The aim names 30 °C, so both set-ups must be at 30 °C and differ only in light colour. That is C and D.
What is the purpose of set-up R in the diagram above?
Answer: to show that anything growing must have come from the seeds
R has everything except the seeds. If something grew in it anyway, the result in P would mean nothing — so R rules that out.
In an experiment, plants given fertiliser grew taller than plants without. Which two conclusions are supported?
Answer: A and B only
A conclusion may report what happened and suggest what it might mean generally. It may not turn one result into a universal law.
Based on the graph above, what would happen if the light were made brighter still?
Answer: The rate would increase very little, if at all.
The curve has flattened, which means something other than light is now limiting the rate. More light would make almost no difference.
A pupil compared two brands of battery by using brand X in a new torch and brand Y in an old torch. Why is the comparison invalid?
Answer: The two torches may use power at different rates, so the batteries were not compared fairly.
An old torch may draw more current or have poorer contacts. Any difference could have come from the torch rather than the battery, so nothing is shown.
Which two changes would most improve an experiment measuring how fast water cools?
Answer: A and B only
Equal volumes make the containers comparable, and fixed intervals make the readings comparable. Changing the room or stopping early destroys both.
Based on the table above, which conclusion is correct?
Answer: Insulation and a lid each reduce heat loss, and together they reduce it most.
Comparing pairs that differ in one thing shows each helps on its own, and W with both is warmest of all at 68 °C.
A set-up that contains everything except the one thing being tested, used as a comparison for all the others, has a special name. What is it called? The ______ .
Answer: control
The comparison set-up without the thing being tested is the control.
In a fair test, everything except the one thing being changed and the one thing being measured must stay the same. Those held-still conditions are the ______ variables. (One word.)
Answer: constant
Conditions held the same throughout are the constant variables.
A pupil wants to find out whether the surface a ball bounces on affects how high it bounces. What must she do?
Answer: Drop the same ball from the same height onto each different surface.
The surface is the one thing to change. The ball and the drop height must be identical every time, or the bounce height cannot be attributed to the surface.