Which of the following instrument has the least count of 0.01 mm in general.
screw gauge
micrometre
metre scale
vernier callipers
A screw gauge has the least count of 0.01 mm.
The scales - vernier callipers, metre scale and screw gauge has the least counts:
Consider a Vernier calipers in which each 1 cm on the main scale is divided into 8 equal divisions and a screw gauge with 100 divisions on its circular scale. In the Vernier callipers, 5 divisions of the Vernier scale coincide with 4 divisions on the main scale and in the screw gauge, one complete rotation of the circular scale moves it by two divisions on the linear scale. Then