State three uses of a vernier callipers.
Three uses of vernier callipers are
Draw a neat labelled diagram of a vernier callipers. Name its main parts and state their functions.
A boy uses a vernier callipers to measure the thickness of his pencil. He measures it to be 1.4 mm. If the zero error of vernier callipers is + 0.02 cm, what is the correct thickness of pencil ?