Quiz on Random vs. Systematic Error

What is the main difference between random error and systematic error?

• Random error varies unpredictably, while systematic error has a consistent value.

• Random error affects accuracy, while systematic error affects precision.

• Random error can be eliminated, while systematic error cannot.

• Random error is predictable, while systematic error is not.

Answer explanation

The correct choice highlights that random error varies unpredictably, leading to fluctuations in measurements, while systematic error consistently skews results in a specific direction, affecting reliability.

Which of the following is a cause of systematic error?

• Instrument calibration

• Air currents

• Environmental factors

• Posture changes

Answer explanation

Instrument calibration is a systematic error cause because it leads to consistent inaccuracies in measurements. Unlike random errors, which vary, systematic errors arise from flaws in the measurement process, such as miscalibrated instruments.

How can systematic error be minimized?

• By using a larger sample size

• By taking multiple measurements

• By calibrating equipment regularly

• By averaging data

Answer explanation

Systematic error can be minimized by calibrating equipment regularly, ensuring that measurements are accurate and reliable. Other options may help with random errors but do not address systematic errors directly.

What type of error is primarily affected by the last significant digit of a measurement?

• Random error

• Systematic error

• Observational error

• Calibration error

Answer explanation

Random error is influenced by the last significant digit of a measurement, as it reflects the inherent variability in repeated measurements. This type of error can lead to fluctuations that affect precision.

Which of the following is an example of random error?

• Using a stretched measuring tape

• Reading a meniscus from different angles

• Drift in electronic equipment

• Not zeroing a balance before use

Answer explanation

Reading a meniscus from different angles introduces variability in measurements due to human perception, making it a random error. Other options involve systematic errors or equipment issues.

What is a common method to deal with random error?

• Setting instruments to zero

• Using controls in experiments

• Taking multiple data points

• Calibrating instruments

Answer explanation

Taking multiple data points helps to average out random errors, providing a more accurate representation of the true value. This method reduces the impact of anomalies in individual measurements.

What is an offset error?

• An error caused by environmental factors

• An error that varies with each measurement

• An error from not reading the meniscus correctly

• An error from not zeroing an instrument before use

Answer explanation

An offset error occurs when an instrument is not zeroed before use, leading to consistent inaccuracies in measurements. This choice correctly identifies the source of the error, unlike the other options.

Which of the following statements is true about systematic error?

• It only occurs in physical measurements.

• It is always unpredictable.

• It affects measurements by the same amount each time.

• It can be completely eliminated.

Answer explanation

Systematic error consistently affects measurements in the same way, leading to a bias. This means it impacts results by the same amount each time, making the statement 'It affects measurements by the same amount each time' true.

What is the effect of random error on measurements?

• It causes consistent bias.

• It affects the accuracy of measurements.

• It leads to variability around the true value.

• It can be corrected by calibration.

Answer explanation

Random error introduces variability in measurements, causing them to scatter around the true value rather than consistently biasing them. This is why the correct choice is that it leads to variability around the true value.

Which of the following is NOT a cause of random error?

• Instrument limitations

• Variations in procedure

• Environmental factors

• Calibration errors

Answer explanation

Calibration errors are systematic errors due to incorrect instrument settings, not random errors. In contrast, instrument limitations, variations in procedure, and environmental factors can all lead to random errors.