Uncertainties and Deviations in Measurement

Five darts strike near the center of the target. Whoever threw the darts is

• accurate

• precise

• both accurate and precise

• neither accurate nor precise

Three measurements are made as 18.425 cm, 7.21 cm and 5.0 cm. The sum in correct significant figures should be written as

• 30.635 cm

• 30.64 cm

• 30.63 cm

• 30.6 cm

The image shown demonstrates...

• High Accuracy & High Precision

• Low Accuracy & High Precision

• High Accuracy & Low Precision

• Low Accuracy & Low Precision

The image shown demonstrates...

• High Accuracy & High Precision

• Low Accuracy & High Precision

• High Accuracy & Low Precision

• Low Accuracy & Low Precision



The accepted value is 15.63. Which correctly describes this students experimental data?

Trial 1: Measurement 12.84;

Trial 2: Measurement 13.02;

Trial 3: Measurement 12.96

• accurate but not precise

• precise but not accurate

• both accurate and precise

• neither accurate nor precise

Answer explanation

True Value = 15.63

3 measurement values is precise but comparing those 3 measurements to the true value suggest that the measurement trials are not accurate.

The accepted value is 29.35. Which correctly describes this students experimental data?

Trial 1: Measurement 29.48;

Trial 2: Measurement 28.97;

Trial 3: Measurement 29.27

• accurate but not precise

• precise but not accurate

• both accurate and precise

• neither accurate nor precise

Answer explanation

True Value = 29.35

3 measurement values is precise and comparing those 3 measurements to the true value suggest that the measurement trials are also accurate.

Which term quantifies the doubt that exists in any reported value of a measurement?

• Precision

• Accuracy

• Error

• Uncertainty

Answer explanation

Uncertainty defines the net effect of the error. It quantifies the doubt that exists in any reported value of the measurement.

Which term describes how close the measured value is to the 'true value'?

• Accuracy

• Precision

• Error

• Uncertainty

Answer explanation

Accuracy specifically measures the proximity or closeness of a measured value to the 'true' or expected value.

What is error in the context of measurement?

• The variability of measurement values.

• The difference between the measured value and the 'true' value.

• The net effect of uncertainty.

• How close the measured value is to the 'true value'.

Answer explanation

Error represents the discrepancy between the measured value and the actual or 'true' value being measured. It quantifies how much the measurement deviates from the ideal or expected value.

What does precision describe in measurement?

• The doubt in the measured value.

• The difference between the measured value and the 'true' value.

• The variability or scatter of measurement values.

• How close the measured value is to the 'true value'.

Answer explanation

Precision characterizes the consistency and repeatability of measurement values. It describes the degree of scatter or variability among multiple measurements of the same quantity.