The least count of a vernier caliper is typically 0.1 mm.
Explanation:
- Least count is the smallest measurement that an instrument can accurately measure
- It is calculated as:
Least Count = Value of 1 main scale division − Value of 1 vernier scale division
Standard Vernier Caliper:
- 1 main scale division (MSD) = 1 mm
- 10 vernier divisions = 9 main scale divisions
- So, 1 vernier division = 0.9 mm
Therefore:
Least Count = 1 mm − 0.9 mm = 0.1 mm
Key Insight:
- Some advanced vernier calipers may have a least count of 0.02 mm, but 0.1 mm is most common in school-level instruments
Conclusion:
The standard least count of a vernier caliper is 0.1 mm, which determines its precision.