Physics A Level
P1 Practical skills at AS Level P1.3 Gathering evidence
Physics A Level
P1 Practical skills at AS Level P1.3 Gathering evidence
When gathering evidence, you should take into account the range of results that you are going to obtain.
If you are investigating the extension of a spring with load, for loads of between $0 N$ and $20 N$, you should take a fair spread of readings throughout that range. For instance, six readings between $12 N$ and $20 N$ would not be sensible because you are not investigating what happens with smaller loads. Equally, taking three readings below $5 N$ and three more between $15 N$ and $20 N$ does not test what happens with intermediate loads.
A sensible set of readings might be at $0 N, 4 N, 8 N, 12 N, 16 N$ and $20 N$. This covers the whole range in equal steps.
Question
1) You are investigating how the current through a resistor depends on its resistance when connected in a circuit. You are given resistors of the following values:
$50\Omega \,,\,100\Omega \,,\,150\Omega \,,\,200\Omega \,,\,250\Omega \,,\,300\Omega \,,\,350\Omega \,,\,400\Omega \,,\,450\Omega \,,\,500\Omega $ You are asked to take measurements with just six of these resistors. Which six resistors would you choose? Explain your choice.