Question

Vernier calipers having $1$ main scale division as $0.1$ cm is designed to have a least count of $0.02$ cm. If $n$ be the number of divisions on vernier scale and $m$ be the length of vernier scale, then:

• A. $n=10,m=0.5cm$
• B. $n=9,m=0.4cm$
• C. $n=10,m=0.8cm$
• D. $n=10,m=0.2cm$

Answer 1

The correct option is C $n=10,m=0.8cm$

Least count, $LC=1MSD-1VSD$
Thus, $0.02=0.1-1VSD$,

$1VSD=0.08$
$1VSD=$ length of vernier scale/number of divisions on vernier scale

$=m/n$
Thus, $m/n=0.08$