A screw gauge has a negative zero error. When the anvil and spindle just touch, the zero of the circular scale is 4 divisions above the reference line. The circular scale has 100 divisions and the pitch is 1 mm. A wire gives PSR = 0.5 mm and CSR = 62. The corrected diameter is:
Options

Question

A screw gauge has a negative zero error. When the anvil and spindle just touch, the zero of the circular scale is 4 divisions above the reference line. The circular scale has 100 divisions and the pitch is 1 mm. A wire gives PSR = 0.5 mm and CSR = 62. The corrected diameter is:

Options

G1 Physics · Accepted Answer

LC = 1/100 = 0.01 mm. Four divisions above the reference line correspond to zero error −0.04 mm, so zero correction = +0.04 mm. Observed reading = 0.5 + 62(0.01) = 1.12 mm. Corrected reading = 1.16 mm.