Question

vernier calipers write down the principle construction and working of it​

Answer 1

Answer:The vernier scale works on the principle of using alignment of line segments displaced by a small amount to make fine measurements. Human eye can easily detect this alignment of lines which is the main fact that drives a vernier.

A vernier scale has a main scale and a vernier scale. The main scale has the normal resolution with a least count of 1 mm. The vernier scale is attached to the main scale which can slide on it and has graduations that are spaced by the same 1 mm only but are slightly displaced with respect to the marks on the main scale. The displacement is the key here.