The zero error in verniel scale is =6×0.1mm=0.6mm (+ve zero error) Note: +ve zero error will have to be subtracted From the reading of the object. Now, the diameter measured with the help of Vernier scale is Given by → M.S.D + V.S.D × L.S ⇒3.2cm+0.1mm×4 =3.24cm The actual diameter is ⇒3.24mm - (zero error) =3.24−0.6=3.18cm