Question

Assertion :The least count of a vernier caliper is 0.1 mm. Reason: $LC=\frac{10MSD}{1VSD}$

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is D Both Assertion and Reason are incorrect

The least count of vernier calipers is always less than one. So, the assertion will be correct.

The least count , $L.C=1MSD-1VSD$

For a vernier calipers, N divisions of vernier scale coincides with (N-1) divisions of main scale. So, $N$ $VSD=(N-1)MSD$ or $1VSD=\left[\right(N-1\left)/N\right]MSD$

So, $L.C=1MSD-\left[\right(N-1\left)/N\right]MSD=\left(1/N\right)MSD$

Thus, reason is incorrect.