A vernier caliper having least count 1/20N cm and one main scale division is 1 mm.

Question

A vernier caliper having least count \(\frac{1}{20N}cm\) and one main scale division is 1 mm, then value of one vernier scale division is 

(1) \(\frac{N+1}{2N}mm\) 

(2) \(\frac{2N+1}{2N}\) mm 

(3) \(\frac{2N-1}{2N}\) mm 

(4) \(\frac{2N+2}{2N}\) mm 

Answer 1

Correct Option is (3) \(\frac{2N-1}{2N}\) mm 

L.C = 1MSD - 1 VSD

\(\frac{1}{20N}\)cm = 1mm - 1 VSD

VSD = 1 mm - \(\frac{1}{2N}\)mm 

= \(\frac{2N-1}{2N}\) mm