Question

In an experiment to measure focal lengths of concave mirror the values of focal length are 17.3 17.8 18.3 18.2 17.9 18.0 cm . Calculate mean absolute error and percentage error. Express the result in a proper way.

Answer 1

Answer:

Here is your answer

The photoes are interchanged please take 2nd photo as the first one

Answer 2

Answer:

• Mean value= 17.3+17.8+18.3+18.2+17.9+18.0/6

= 107.5/6

=17.9 cm.

• Absolute error:a1=17.9-17.3=0.6 cm.

a2=17.9-17.8=0.1 cm.

a3=17.9-18.3=-0.4 cm.

a4=17.9-18.2=-0.3 cm.

a5=17.9-17.9=0 cm.

a6=17.9-18.0=-0.1 cm. Mean absolute error =a1+a2+a3+a4+a5+a6/6

=0.6+0.1+0.4+0.3+0+0.1/6

= 1.5/6

=0.25 cm.

• Relative error=0.25/17.9

=0.01 cm.

• Correct length=17.9+_0.25 cm.
• % error=0.25/17.9×100

=1.39%