Question

In a Vernier callipers, 1 cm of the main scale is divided into 20 equal parts. 19 divisions of the main scale coincide with 20 divisions on the vernier scale. Find the least count of the instrument.

• A. 0.001 cm
• B. 0.002 cm
• C. 0.01 cm
• D. 0.0025 cm

Answer 1

The correct option is D 0.0025 cm

If $n$ VSD coincide with $(n-1)$ MSD then least count or vernier constant is

$VC=(1-\frac{n-1}{n})\times \left(valueof1MSD\right)=(1-\frac{19}{20})\times \frac{1}{20}=0.0025cm$