Question

The main scale of vernier callipers is calibrate in mm and 19 division of main scale are equal in length to 20 divisions of vernier scale. In measuring the diameter of a cylinder by this instrument, the main scale reads 35 divisions and 4th division of vernier scale coincides with a main scale division. Find least count and radius of cylinder​

Answer 1

Given,

i) VSR = 20 division

MSR= 19 division

Therefore value of 1 main scale division = 1 mm

Since,

L. C= 1/20= 0.05mm

= 0.005 cm

ii) MSR = 35/20 =1.75cm

V. S. R= 4th div

T. R = MSR+VSR* LC

= 1.75+4(0.005)

= 1.75+ 0.020

= 1.77cm