Question

A scientist performs an experiment and takes 50 readings. He repeats the same experiment and now takes 200 readings. By doing so:

• A. Both the systematic and random errors remain unchanged.
• B. Both the systematic and random errors are reduced by a factor of 1/4.
• C. The systematic error remains unchanged and random error is reduced by a factor of 1/4.
• D. The systematic is reduced by a factor of 1/4 and random error remains unchanged.

Answer 1

Answer: (C)

The systematic error remains unchanged and random error is reduced by a factor of 1/4.

Answer 2

Systematic error is due to faculty instrument, parallax etc. and is always unidirectional. It can not be reduced by increasing number of readings. Random error or probable error can be positive or negative in each reading and large number of reading reduced its effect.