Uncertainties and errors

What are direct measurements?

• Measurements that are calculated using other measurements
• Mistakes that occur during the experimental setup
• Significant and obvious mistakes that occur during the measurement process
• Measurements that are taken directly from instruments

What is an indirect measurement?

• Measurement obtained by combining base units
• Measurement obtained by measuring something else

• Measurement obtained by estimating
• Measurement obtained by using derived units

Which of the following is an example of a random error?

• Recording data incorrectly
• Misreading an instrument
• Fluctuations in environmental conditions
• Setting up an experiment improperly

What is systematic error?

• Random error in measurements
• Error that consistently occurs in the same direction
• Error caused by faulty equipment
• Error that occurs due to human error

What is a random error?

• An unpredictable and fluctuating error
• An error caused by limitations in the precision of measurement instruments
• An error that consistently shifts measurements in a particular direction
• An error due to human limitations in reading instruments

Choose TWO correct ways to overcome systematic errors and random errors

• Use inaccurate measuring instrument

• Take average reading from a few reading of measurement

• Repeat measurement using different measuring tools

• Eye level must be below the measurement scale

Choose TWO correct examples of systematic errors.

• Inaccurate measuring instrument

• Parallax error

• Observer's eye not perpendicular to scale reading

• Zero error

What are the causes of zero error?

• Lack of training in using the equipment

• Improper handling of the equipment

• Incorrect reading of the instrument

• Incorrect calibration, wear and tear of equipment, or environmental factors

The dashed line in the image represents

• The error bars

• The uncertainty

• Line of best fit

• Line of worst 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)