**Error in Measurement – **

The error in a measurement is equal to the difference between the true value and the measured value of the quantity. **Error = True value – Measured Value**

**Elimination of Error **

The error may be positive or negative so random errors can be minimised by repeating measurements a large number of times. Thus the arithmetic mean of all measurement can be taken as the true value of the measured quantity.

a_{mean} = (a_{1}+a_{2}+…a_{n})/n**Absolute Error** –

The magnitude of the difference between the true value of the quantity measured and the individual measured value is called absolute error.