Question

What is true about random errors?

(a) Sign of error can be predicted

(b) Probability of occurrence of same absolute value is not equal for negative and positive errors

(c) Constant in magnitude

(d) Arithmetic mean in a measurement series approaches zero as measurement number increases

I have been asked this question during an online interview.

The question is from Evaluating Uncertainty in Measurement in division Evaluating Uncertainty in Measurement of Engineering Metrology

Answer 1

Right option is (d) Arithmetic mean in a measurement series approaches zero as measurement number increases

The explanation: Random errors can be caused by friction and may be due to play in the linkage of instruments. These errors are variable in sign and magnitude. These are sometimes negative and sometimes positive. Its sign cannot be predicted.