Question

consider a vernier calliper that has 30 equal divisions on a vernier scale coinciding with 27 main scale divisions. If a main scale is a millimetre scale, what is the least count of this instrument?

Answer 1

Dear student

$$\begin{gathered} Leastcountis \\ LC=1Mainscaledivision-1vernierscaledivision \\ 30VSD=27MSD \\ 1VSD=\frac{27}{30}MSD \\ lengthof1vernierdivision=\frac{27}{30}\times 1mm \\ LC=1mm-\frac{27}{30}mm \\ LC=\frac{30-27}{30}=\frac{3}{30}=\frac{1}{10}=0.1mm \\ Regards \end{gathered}$$