Explore key concepts of measurement accuracy, precision, and resolution through scenario-based questions. This quiz helps deepen your understanding of how these factors impact data reliability and instrument selection in scientific and technical contexts.
A digital weighing scale consistently shows 100.0 grams for an object that actually weighs 101.0 grams. Which term best describes this scale's performance?
Explanation: The scale provides consistent readings that are close to each other, demonstrating high precision. However, its measurements are consistently off from the true value, which means it lacks accuracy. 'High accuracy, low precision' is incorrect because the readings are not close to the true value. 'High precision, high accuracy' would require both repeatable and true results. 'Low precision, low accuracy' would be evident if measurements varied widely and missed the true value.
If a thermometer displays temperatures to the nearest 0.01°C, but repeated measurements of the same water sample range from 25.40°C to 25.80°C, what does this indicate?
Explanation: The thermometer’s ability to show readings to 0.01°C means it has high resolution, but since measurements vary by 0.40°C for the same sample, it has low precision. 'Low accuracy, high precision' doesn’t fit as the measurements fluctuate. 'High accuracy, low resolution' is incorrect since the device has high resolution. 'High precision, high accuracy' is not supported by the variable readings.
A digital voltmeter can show voltage readings with up to three decimal places (e.g., 7.128 V). What characteristic does this detail represent?
Explanation: Resolution refers to the smallest discernible change an instrument can display, illustrated here by showing values to three decimal places. Precision relates to how close repeated measurements are to each other. Accuracy is about closeness to the true value, which is not implied in this question. 'Exactitude' is a non-standard term not typically used in measurement sciences.
When a systematic calibration error is present in a measuring device, which aspect of measurement is primarily affected?
Explanation: Systematic errors cause all measurements to be off from the true value in the same direction, directly reducing accuracy. Precision concerns measurement repeatability, which can still be high with systematic errors. Resolution is about measurement detail, not correctness. 'Consistency' is more closely related to precision than accuracy.
Instrument A reports measurements as 12.500, 12.501, and 12.499, while Instrument B gives 12.4, 12.8, and 13.2 for the same object. What can you conclude about Instrument A?
Explanation: Instrument A delivers very similar readings each time, indicating high precision. Lower resolution would be seen if it reported measurements to fewer decimal places. There's no information about accuracy since the true value is not provided. Systematic error would cause all readings to be off the true value, which is not indicated here.