Question

What is least count of the measuring instruments?

Answer 1

The error in the measurement by an instrument is equal to least count of the instrument. For example, a metre scale has smallest division 1 mm. This represents the least count or the absolute error in the measurement. Vernier callipers consist of two scales; main scale and vernier scale. The least count of the instrument is the smallest distance between two consecutive divisions and is equal to 1 MSD - 1 VSD. Screw gauge contains the main scale and a circular scale. The circular scale is divided into a number of divisions. The least count of a screw gauge is pitch/number of circular scale divisions.