Question

. A vernier callipers has its main scale graduated in
mm and 10 divisions on its vernier scale are equal
ir length to 9 mm. When the two jaws are in contact,
the zero of vernier scale is ahead of zero of main
scale and 3rd division of vernier scale coincides with
a main scale division. Find : (i) the least count and
(ii) the zero error of the vernier callipers.​

Answer 1

Value of one main scale division is 1 mm

10 div of vernier scale =9 mm.

1 div of vernier scale =9/10 mm.

Least count =L.C.= Value of one main scale division – Value of one vernier scale division

L.C= 1−

10

9

​

=1 mm−0.9 mm=0.1 mm=0.01 cm