Physics Error Definitions

Question 1

What is a random error + examples

Answer 1

An error that effects results at random, oddly enough
Examples:
A sudden gust of wind
Readability of the equipment (one off)
Observer being less than perfect

Question 2

What is a systematic error + examples

Answer 2

An error that occurs with each reading 
Examples
Observer being less than perfect the same way each time
Instrument with a offset zero error
An improperly calibrated instrument

Question 3

Measurement error

Answer 3

The difference between a measure value and the true value

Question 4

Anomalies

Answer 4

These are values in a set of results which are judged not to be part of the variation caused by random uncertainty

Question 5

Random error AQA definition

Answer 5

These cause readings to be spread about the true value, due to results varying in an unpredictable way from one measurement to the next.
Present during any measurement, and cannot be corrected.

Question 6

How can you reduce random errors

Answer 6

By making more measurements and calculating a new mean

Question 7

Systematic error AQA definition

Answer 7

These cause readings to differ from the true. Alice by a consistent amount each time a measurement is made. Sources can include the environment, methods of observation or instruments used.

Question 8

How to prevent systematic errors

Answer 8

Cannot be prevented by just simple repeats - if a systematic error is suspected, the experiment should be repeated using a different set of equipment/using a different method, and the results compared.

Question 9

Zero error

Answer 9

Any indication that a measuring system gives a false reading when the true value of a measured quantity is zero, i.e. The needle on an ammeter failing to return to zero when no current flows.
A zero error may result in systematic uncertainty

Question 10

Precision

Answer 10

Precise measurements are ones in which there is very little spread around the mean value. Precision depends only on the extent of random errors - it gives no indication of how close results are to the true value

Question 11

Repeatability

Answer 11

A measurement is repeatable if the original experimenter repeats the investigation using same method and equipment and obtains the same results

Question 12

Reproducibility

Answer 12

A measurement is reproducible if the investigation is repeated by another person, or by using different equipment or techniques, and the same results are obtained

Question 13

Resolution

Answer 13

This is the smallest change in the quantity being measured (input) of a measuring instrument that gives a perceptible change in the reading.

Question 14

Accuracy

Answer 14

A reading is considered accurate if it is judged to be close to the true value