Question

In a measurement, random error
A) Can be decreased by increasing the number of readings and averaging them.
B) Can be decreased by changing the person who takes the reading.
C) Can be decreased by using a new instrument.
D) Can be decreased by using a different method in taking the reading.
E) Cannot be decreased.

Answer 1

Random errors are those errors that shift each measurement from its correct value by a random amount. Random errors can affect the reliability of measurement.

Complete step by step answer:
Random errors are the errors that shift the final measurement a little bit here and there. These errors can be corrected by taking a good number of readings and averaging them. Averaging the readings give the final reading with nearly precise value.
Let us take an example. A measurer measures the length of a line by using a ruler. The measurer puts the ruler in a way that the endpoint of the line coincides with the second line of the ruler. The measurer makes a random error here which is due to insufficient precision.
Hence, in a measurement, random error can be decreased by increasing the number of readings and averaging them.

Therefore, option (A) is correct.

Additional Information:
Random errors can be found mainly due to the following causes:
Random errors arise from the environment- These types of errors occur when the measurement is taken such conditions like air pressure, temperature, humidity, vibrations, etc. These conditions can’t be made constant for a certain measurement.
Random errors due to reaction time-Some measurements are affected due to the early or late response of the measurer.
Random errors due to insufficient precision- Measuring a measure within the two marking points will give insufficient precision. Sometimes the measurer makes errors while taking measurements.

Note:
Random errors will be decreased when the measurer takes a good number of readings. These types of errors are mainly known as human errors( either from the human side or from nature).