Question

give the value of smaller division on main scale and the total no. of division on vernier scale of the instrument used in experiment.

Answer 1

Smallest division on the main scale is 0.1cm. L.C=Value of one main scale division -value of one Vernier scale division  =1mm -9/10mm=1mm-0.9mm Or , L.C=Value of one main scale division or total number of divisions on the Vernier scale =1mm/10=0.1mm or  0.01cm

Answer 2

Least count:

The value of smaller division on main scale and the total no. of division on vernier scale of the instrument is used as Least Count of the instrument.

Pitch ÷ Number of Vernier scale divisions = Length of one main scale division - Length of one Vernier scale division = Least count

In an instrument, error may occur because of manufacturing errors in the instrument. For example, when the jaws do not fit perfectly then error occurs. When there is no such error zero error occurs.