In a vernier callipers N divisions of vernier scale coincide with `N-1` divisions of main scale (in which length of one divisions is 1mm). The least count of the instrument should be

Options

A. N
B. `N-1`
C. `1/(10N)`
D. `1/(N-1)`

Answer

C

Explanation

NVD=`(N-1)Sd," "1VD=((N-1)/N)SD`
V.C.=least count `=1SD-1VD`
`V.C.=(1-(N-1)/N)SD=1/NSD=0.1/10Ncm" " or LC=(1MSD)/N=(1mm)/N=1/(10N)cm`