Question

1 cm on the main scale of a vernier callipers is divided into 10 equal parts. If 10 divisions of vernier coincide with 8 small divisions of main scale, then the least count of the calliper is.

Answer 1

If 1 cm on the main scale of a vernier callipers is divided into 10 equal parts. If 10 divisions of vernier coincide with 8 small divisions of main scale, then the least count of the calliper will be 0.02 cm

Least Count refers to the smallest distance that can be measured using an instrument. It indicates the precision of any instrument. Least count can calculated using the formula.

Least Count = Length of 1 MSD – Length of I VSD

Where, MSD = Main Scale Division and VSD = Vernier Scale Division  

Width of each division =1 cm×1/10 =0.1 cm

Least count of the vernier is equal to the 10-8/10  times the value of each division.

Therefore,  Least count =2/10×0.1 cm=0.02 cm