Physics Quiz on “Accuracy, Precision of Instruments and Errors in Measurement”.
1. In an experiment, it is found that the experimental value is very close to actual value, hence the experimental value can be called _____
a) Accurate
b) Precise
c) Suitable
d) Mean
Answer: a
Clarification: Accuracy is the degree to which a value is near to the actual or standard value. Hence if the experimental value is very close to the actual value, the measurement can be called accurate.
2. What is the reason for the occurrence of systematic errors in an instrument ?
a) No use for a long time
b) High use
c) Manufacturing fault
d) Delivery fault
Answer: b
Clarification: Systematic errors arise due to high use of the instrument. It can also be present because of careless handling.
3. How are systematic errors removed usually for an instrument?
a) By replacing it
b) By re-calibrating it
c) By using a repairing service
d) By not using it for some time
Answer: b
Clarification: Systematic errors arise due to careless or overuse of an instrument. It can easily be removed by re-calibrating the instrument and maintaining it properly.
4. In 5 experiments with the same objective, the values obtained are very near to each other. These values can be called ____
a) Precise
b) Accurate
c) Average
d) Invalid
Answer: a
Clarification: Precision refers to the how close the data points or numbers in a set are. In this case the values obtained are very close to each other, hence they are precise.
5. Range of an instrument is _____
a) The minimum value that can be measured
b) The maximum value that can be measured
c) All values starting from the minimum to the maximum that can be measured
d) The average of all values that can be measured
Answer: c
Clarification: Range refers to all values starting from the minimum to the maximum that can be measured. Range is sometimes also referred to as span.
6. Usually how many types of errors are present in scientific measurements?
a) 2
b) 3
c) 4
d) 5
Answer: b
Clarification: There are three types of scientific errors – Random errors, Systematic errors and Blunders. Out of the three, systematic errors are the easiest to remove.
7. What is least count of an instrument?
a) The lowest value that can be measured accurately
b) The greatest value that can be measured accurately
c) Half of the lowest value that can be measured accurately
d) Mean of the lowest and highest values
Answer: a
Clarification: The least count of an instrument is the lowest value that can be measured accurately. For example, if the lowest value that can be measured by a ruler is 1 mm, then the least count is 1 mm.