Vernier Callipers and Zero Error

2025 1 question

1. Consider the diameter of a spherical object being measured with the help of a Vernier callipers. Suppose its 10 Vernier Scale Divisions (V.S.D.) are equal to its 9 Main Scale Divisions (M.S.D.). The least division in the M.S. is $0.1\text{ cm}$ and the zero of V.S. is at $x = 0.1\text{ cm}$ when the jaws of Vernier callipers are closed. If the main scale reading for the diameter is $M = 5\text{ cm}$ and the number of coinciding vernier division is 8, the measured diameter after zero error correction, is: