Question

Show that a screw gauge of pitch 1 mm and 100 divisions is more precise than a vernier caliper with 20 divisions on the sliding scale.

Answer 1

Least count of vernier calliper = 1M.S.D - 1 V.S.D
given, 1 division of main scale consider with 20 divisions of vernier scale
so, least count = 1M.S.D - 19/20 M.S.D = 1/20 M.S.D
We know, 1 M.S.D = 1mm
so, least count = 1/20 mm = 0.05 mm

Least count for screw guage = pitch/number of divisions
= 1mm/100 = 0.01 mm

Hence, you can see that screw guage is more precise than vernier calliper