Question

We measured the thickness of a sheet by the Venire Calipers in successive measurement. The readings turned out to be 1.2 mm, 1.4 mm, 1.5 mm, 1.8 mm and 1.6mm. Calculate the absolute error, relative error and percentage error

Answer 1

The mean thickness of a sheet measured by vernier Calipers = $\frac{1.2+1.4+1.5+1.8+1.6}{5}=\frac{7.5}{5}=1.5$
The errors in the measurement are
1.2-1.5 =-0.3 mm
1.4-1.5 = -0.1
1.5-1.5 =0
1.8-1.5=+0.3
1.6-1.5 = +0.1

The arithmetic mean of all absolute error is taken as the final or mean absolute error of the value of a physical quantity
0.3+0.1+0+0.3+0.1/5 = 0.16 = 0.2 mm
so its values lies between =$1.5\pm 0.2$
The relative error = absolute error/ mean error = 0.2/1.5 = 0.13
so percentage error = relative error * 100 = 13%