Question

The zeroth division of a vernier scale lies between the${40}^{\mathrm{th}}\mathrm{and}{41}^{\mathrm{st}}$main scale division. Then, the $\mathrm{M}.\mathrm{S}.R=4\mathrm{cm}\mathrm{if}\mathrm{M}.\mathrm{S}.\mathrm{D}.=1\mathrm{mm}$.

• A. True
• B. False

Answer 1

The correct option is A True

To measure any distance by a vernier caliper.

1. Place the object in between two external (long) jaws and tighten the lock screw.
2. Measure the main scale reading and take the reading of the vernier scale and calculate by the formula
3. $$\begin{gathered} \mathrm{Length}\left(\mathrm{L}\right)=\mathrm{M}.\mathrm{S}.\mathrm{R}.+(\mathrm{V}.\mathrm{S}.\mathrm{R}.\times \mathrm{L}.\mathrm{C}.) \\ \mathrm{Where}\mathrm{LC}\mathrm{is}\mathrm{least}\mathrm{count} \\ \mathrm{VSR}\mathrm{vernier}\mathrm{scale}\mathrm{reading} \\ \mathrm{MSR}\mathrm{main}\mathrm{scale}\mathrm{reading} \end{gathered}$$
4. If the zeroth division of the vernier scale lies between the $40\mathrm{th}\mathrm{and}41\mathrm{th}$main scale division, we take the immediate left value on the main scale.
5. This clearly means the measurement of the main scale is $4\mathrm{cm}\mathrm{or}40\mathrm{mm}$.