Least count of a vernier callipers
One main scale division is 1 mm and 10 vernier divisions match 9 main scale divisions, so the least count is 0.1 mm or 0.01 cm.
Least count
0.1mm
= 0.01 cm
1 mm / 10 = 0.1 mm
Least count = 1 main scale division / number of vernier divisions.
Least count = 1 main scale division / number of vernier divisions
A vernier callipers is used for lengths, diameters and depths up to about 15 cm. The working for the textbook numbers is 1 mm / 10 = 0.1 mm.
Other instruments
Vernier callipers: quick answers
What is the least count of a vernier callipers?
One main scale division is 1 mm and 10 vernier divisions match 9 main scale divisions, so the least count is 0.1 mm or 0.01 cm. Least count = 1 main scale division / number of vernier divisions.
How do I find the least count of my vernier callipers?
Least count = 1 main scale division / number of vernier divisions. For the instrument in front of you, read the scale and use your own numbers in the tool above.
Why does the least count matter?
The least count is the smallest reading you can make, so it sets the smallest error in a single measurement. Vernier callipers measures lengths, diameters and depths up to about 15 cm.