Explain accuracy and precision in measurement.

Explanation

Measurement is the foundation of all experimental science and technology.
Uncertainty in measurement is called error.
How close the measured value is to the true value of the quantity is called accuracy.
Upto what limit (or resolution) the quantity is measured is called precision.
Accuracy in measurement depend on resolution of measuring instrument.
For example true value of certain length is near 3.678 cm. When this length is measured with instrument with resolution of 0.1 cm measured value is found to be 3.5 cm and same when measured with resolution of 0.01 cm, value is found to be 3.38 cm.
Here first observation is more accurate because it is near to true value.
True value = 3.678 cm
When measured with device of 0.01 cm resolution, measured value = 3.38 cm.
Error in measurement = 0.298 cm
Hence, measurement obtained by instrument with 0.1 cm resolution is more accurate because it is more near to true value but in that precision is less. (Value of precision depend on resolution, when resolution is less, precision is more) where as measurement obtained by instrument with 0.01 cm resolution is more precise,