The Vernier of a circular scale has 30 divisions coinciding with 29 main-scale divisions. If each main-scale division is (1/2)°, find the least count.
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Question

The Vernier of a circular scale has 30 divisions coinciding with 29 main-scale divisions. If each main-scale division is (1/2)°, find the least count.

G1 Physics · Accepted Answer

For a direct Vernier, 30 VSD = 29 MSD, so 1 VSD = 29/30 MSD. Least count = 1 MSD − 1 VSD = (1/30) MSD = (1/30)(0.5°) = 1 minute of arc. Correct answer: B.