Question

While measuring the length of a copper rod using Vernier calipers, the zero of the Vernier scale was found to be between 4.6 cm and 4.7cm on the main scale. The 6th division of the Vernier scale is found to coincide with a division on the main scale. Find the length of the rod if the least count is 0.01 cm.

Answer 1

Step-1 given data

Main scale reading(M.S.R.) $$\begin{gathered} =4.6\mathrm{cm} \\ =46mm \end{gathered}$$

(Note $1\mathrm{cm}=10\mathrm{mm}$)

Vernier coincides with the main scale is $(\mathrm{V}.\mathrm{C}.\mathrm{D}.)=6$

Least count $\left(\mathrm{L}.\mathrm{C}\right)=0.01\mathrm{cm}$

$=0.1\mathrm{mm}$

Step-2 Finding the length of the rod

Length of rod $\left(\mathrm{L}\right)$

$\mathrm{L}=\mathrm{M}.\mathrm{S}.\mathrm{R}.+\left(\mathrm{V}.\mathrm{C}.\mathrm{D}\right)\times \left(\mathrm{L}.\mathrm{C}.\right)$

$=46+6\times 0.1$

$=46.6\mathrm{mm}$

$=4.66\mathrm{cm}$

Hence, the length of the copper rod is $4.66\mathrm{cm}.$