Question

A Vernier calipers has 1 mm marks on the main scale. It has 20 equal divisions on the Vernier scale which match with 16 main scale divisions. For this Vernier calipers, the least count is-

• A. $0.02mm$
• B. $0.05mm$
• C. $0.1mm$
• D. $0.2mm$

Answer 1

The correct option is D $0.2mm$

Least count of vernier scale is the difference between one main scale division and vernier scale division.
$LC=1MSD-1VSD$
$LC=1MSD-\frac{16}{20}MSD$
$LC=\frac{4}{20}MSD$
$LC=\frac{4}{20}\times 1mm$ .....................(given)
$LC=0.2mm$