Accuracy of measurement is determined by:

(A) Absolute error

(B) Percentage error

(C) Both

(D) None of these

Let x be the actual length of an object and x_m be the measured length.

Absolute Error:

Absolute error is the difference between the measured value and the actual value of a quantity. It is given by:

This shows how much the measured value deviates from the actual value.

Percentage Error:

Percentage error compares the difference between the measured and actual values relative to the actual value. It can be calculated as:

or

Key Difference:

• Absolute error shows the actual deviation of the measured value from the true value.
• Percentage error indicates how significant this deviation is relative to the actual value.

Since accuracy measures how close a measured value is to the true value, it is usually determined using percentage error.