# Practical skills - paper 1 and 2 Flashcards

## To revise key practical terms (Paper 1 and 2)

Define an independant variable

The ** one** variable that you change

Define a dependant variable

The variable that you measure

Define a control variable

Any variable you keep the same to make it a fair test

Define directly proportional

If one variable increases the other variable increases at the same rate. eg if x doubles then y must double.

A graph would be a __straight line**__ through the __**origin__

Define inversely proportional

If one variable increases the other variable decreases at the same rate. eg if x doubles then y must halve

Define an anomalous result

An result which does fit the pattern of trend

What should you do if you have an anomolus result?

Repeat the reading

Ignore it when calculating the average

Circle on the graph and not include it in your line of best fit

Define interval

The spacing between measurements eg 0, 10, 20, 30 40, 50 cm would have an interval of 10 cm

Define range

The maximum and minimum values eg 0, 10, 20, 30, 40, 50 cm would have a range of 50 to 0 cm

Define resolution

The smallest change that can be measured with a particular piece of equipment

If a stop clock reads 18.72 seconds, what is its resolution?

0.01 s

If a voltmeter reads 3.6 V what is its resolution?

0.1 V

How can the uncertainty in a measurement be measured?

Half of the range

When should you draw a line graph

When both variables are continuous

When should you draw a bar graph

If one of the variables is discrete or categoric