PART - 1 CH - 1 Some Basic Concepts of Chemistry — Chemistry STD 11 Science — Question

There is some uncertainity in every experimental measurement. But the results of experimental measurements need to be accurate and realistic.
Precision : The closeness of different measurements of any quantity is called precision.
Accuracy : The similarity of a particular experimental value with actual value is called its accuracy. Example : If correct value result is 2.00 gm and the two measurement results of student A are 1.95 gm and 1.93 gm , then these values are accurate because they are close to each other but are not exact because these values are different from actual value. Two results of students B's measurement are 1.94 gm and 2.05 gmwhich are neither accurate nor realistic. Student C's two measurement results are 2.01 gm and 1.99 gm which are both accurate and true.