Least count of a vernier when n divisions of one scale match n - 1 (or n + 1) divisions of the other

1. A.
   $\frac{10\text{~na~}}{(n - 1)}$
2. B.
   $\frac{10a}{(n - 1)}$
3. C.
   $\left( \frac{n - 1}{10n} \right)$ a
4. D.
   $\frac{10a}{n}$

Tap an option to check your answer.

1. A.
   $\frac{n}{(n + 1)}$
2. B.
   $\frac{m}{(n + 1)}$
3. C.
   $\frac{1}{(n + 1)}$
4. D.
   $\frac{m}{n(n + 1)}$

Tap an option to check your answer.