Errors and practical physics A level

A measurement result is considered ________ if it is judged to be close to the true value. It is influenced by random and systematic errors.

• Precise

• Accurate

• An error

• Resolution

A quality denoting the closeness of agreement (consistency) between values obtained by repeated measurement. It is influenced by random effects and can be expressed numerically.

• Repeatability

• Precision

• Uncertainty

• Resolution

The smallest change in the quantity being measured that causes a perceptible change in the output of the measuring device. This is usually the smallest measuring interval.

• Resolution
• Repeatability
• Precision
• Error

Any measurement will have some ____________. This will come from variation in the data obtained and be subject to systematic or random effects. This can be estimated by considering the instruments and the method and will usually be expressed as a range such as 20 ± 2 °C.

• Error

• Precision

• Reproducibility

• Uncertainty

The dashed line in the image represents

• The error bars

• The uncertainty

• Line of best fit

• Line of worst fit

The solid blue lines in the image represent...

• The error bars

• The uncertainty

• Line of best fit

• Line of worst fit

The black lines either side of the points are

• The error bars

• The spread of data

• Line of best fit

• Line of worst fit

To find the uncertainty in the gradient..

• Use y=mx + c

• Look at the spread of the error bars

• Gradient of line of worst fit x 2

• Gradient of line of worst fit - gradient of line of best fit

Which of these statements is true

• Anomalous data should be included when drawing any trends

• The line of worst fit only must pass through all error bars (excluding anomalous data)

• The line of best fit only must pass through all error bars (excluding anomalous data)

• Both the line of best fit and the line of worst fit must pass through all error bars (excluding anomalous data)

When you add or subtract two quantities, you...

• add or subtract the uncertainty

• add or subtract the percentage uncertainty

• multiply the two percentage uncertainty