Question

There are two Vernier Calipers both of which have $1cm$ divided into $10$ equal divisions on the main scale. The Vernier scale of one of the calipers has $25$ equal divisions coinciding with $27$ divisions on the main scale; while the Vernier scale of the other has $25$ divisions coinciding with $23$ divisions on the main scale. You have to decide which pair of data correspond to which calipers by referring to the figures below:

• A. The smallest reading that can be taken on $C_1$ is $0.004cm.$ .
• B. The smallest reading that can be taken on $C_2$ is $0.008cm.$
• C. The reading indicated by $C_1$ is $\mathrm{2.552.}$
• D. The reading indicated by $C_2$ is $\mathrm{2.548.}$

Answer 1

Answer: (A)

The reading on $C_1$ is $=2.5+6\times \left(1-\frac{23}{25}\right)\times 0.1=2.548cm$ and the reading on $C_2$ is $=2.6+6\times \left(1-\frac{27}{25}\right)\times 0.1=2.552cm.$