Question

Let A represents the least count of a vernier caliper whose
10 main scale divisions are equal in length to 12 vernier
scale divisions, and one main scale division is equal to 1
mm. Say B represents the least count of a screw gauge
with 25 circular scale divisions and a pitch of 1 mm, A - B
in mm is​

Answer 1

Step-by-step explanation:

How much we know about the Vernier calipers?

Measurement is a fundamental part of all scientific experiments, including Physics. At one extreme, our vast universe extends this measuring exercise to light-years, the distances so vast that we cannot see them from our eyes. On the other extreme of the smallest distances, new discoveries are pushing it down to femto-meter (10-15 m) or even less. These distances are so small that we cannot see them from our eyes. At every 1-2 order of magnitude change in distance, our instruments to measure the distances accurately can differ. When the distances, we want to measure, are in the range of 10-2 mm to 1 mm, we use Vernier Calipers and Screw Gauge for precise measurement. In this article, we are going to focus on these measuring instruments only.