A direct vernier is constructed such that 50 vernier scale divisions are equal to 48 main scale divisions. One main scale division is 0.50 mm. A rod gives a main scale reading of 18.00 mm and the 37th vernier division coincides with a main-scale mark. If the positive zero error is +0.06 mm, the corrected diameter of the rod is:
Options

Question

A direct vernier is constructed such that 50 vernier scale divisions are equal to 48 main scale divisions. One main scale division is 0.50 mm. A rod gives a main scale reading of 18.00 mm and the 37th vernier division coincides with a main-scale mark. If the positive zero error is +0.06 mm, the corrected diameter of the rod is:

Options

G1 Physics · Accepted Answer

50 VSD = 48 MSD, so 1 VSD = (48/50)(0.50) = 0.48 mm. Least count = 0.50 − 0.48 = 0.02 mm. Observed reading = 18.00 + 37(0.02) = 18.74 mm. Corrected reading = 18.74 − 0.06 = 18.68 mm.