What is the use of thin strip moving behind the main scale of vernier caliper?

Answer 1

That is the intelligent technique applied by Vernier. We have seen 1 cm gap. That has been divided into ten equal parts. So each part is 1 mm. That too could be sensed. Even that 1 mm could be divided into two equal halves with markings. But now we need 1/10 of a mm. Will it be possible to have such 10 equal gaps within that 1 mm gap? No not at all possible. But I'd like to measure such a fine distance. What can I do?

Now let us take 9 mm and divide that length into 10 equal parts. That markings could be done easily. Now each gap would be 0.9 mm. As we keep the extreme end marking ie 0 reading of vernier along with 0 of main scale, then the other extreme would coincide with 9 mm marking. Ok what about first division of vernier? It will be just before the 1 mm marking by a gap 1-0.9 = 0.1 mm. So as we slide the vernier through small distance such that first division of vernier coincides with 1 mm marking, then we are so sure that we have slided the vernier by 0.1 mm. See we have succeeded in getting even that 0.1 mm so accurately without direct markings. That is the intelligence of mankind inherent by nature.

Answer 2

The strip that enables us to measure the depths of objects such as tubes or the depths of liquid inside a container

Answer 3

Vernier graduation