Correct option is C
The
least count of a Vernier caliper is the
smallest measurement that the instrument can accurately read. It is the difference between one division on the main scale and one division on the Vernier scale. The least count determines the precision of the instrument, typically
0.02 mm for most standard Vernier calipers.
Formula for Least Count:
Least Count = Value of 1 Main Scale Division − Value of 1 Vernier Scale Division
For a common Vernier caliper:
· Main scale division = 1 mm
· 50 Vernier scale divisions = 49 mm on the main scale
Least Count = 1 mm/50 = 0.02 mm
A vernier calliper consists of two main parts:
· the main scale engraved on a solid L-shaped frame
· the vernier scale that can slide along the main scale.
It is commonly used to measure accurately:
· outside diameters of shafts
· thicknesses of various parts
· diameters of holes or rings
· internal dimensions of hollow jobs or articles
