Keywords

Question 1

Resolution

Answer 1

The resolution is the smallest division on the instrument

Question 2

Accuracy

Answer 2

A measurement result is considered accurate if it is judged to be close to the true value.

Question 3

Random error

Answer 3

These cause readings to be spread about the true value, due to results varying in an unpredictable way from one measurement to the next.

Random errors are present when any measurement is made, and cannot be corrected. The effect of random errors can be reduced by making more measurements and calculating a new mean.

Question 4

Systematic error

Answer 4

These cause readings to differ from the true value by a consistent amount each time a measurement is made.

Sources of systematic error can include the environment, methods of observation or instruments used.

Systematic errors cannot be dealt with by simple repeats. If a systematic error is suspected, the data collection should be repeated using a different technique or a different set of equipment, and the results compared.

Question 5

Zero error

Answer 5

Any indication that a measuring system gives a false reading when the true value of a measured quantity is zero, eg the needle on an ammeter failing to return to zero when no current flows.

A zero error may result in a systematic uncertainty.

Question 6

Uncertainty

Answer 6

range of values likely to enclose the true value