Value of N divison on a vernier scale is equal to (N-1) scale on main scale of vernier. If value of 1 scale on main scale is 1 mm then leas count will be....

Options

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

Explanation

Least count= {value of division on main scale}-{value of 1 division on vernier scale}
`:.L*C=1MSD-1VSD`
`=1MSD-((N-1)/(N))MSD`
`[{:( :. N VSD=(N-1)MSD),( :. 1VSD=((N-1)/(N))MSD):}]`
`L*C=((N-N+1)/(N))MSD`
`=(1)/(N) MSD`
`=(1)/(N)x1mm`
`=(1)/(N)xx(1)/(10) cm`
`=(1)/(10N) cm`