The distance moved by the screw of a screw gauge is 2 mm in four rotations and there are 50 divisions on its circular scale. Before starting the measurement, it is found that when the two jaws of the screw gauge are brought in contact 48th division of circular scale coincides with main scale line with zero of the main scale is barely visible. When a plate is placed between the jaws, main scale reads 1 mm and 6th division of the circular scale coincides with the main scale line. Thickness of the plate is

Options

A. 1.06 mm
B. 1.04 mm
C. 1.08 mm
D. 1.12 mm

Answer

C

Explanation

Least count = `0.5/50 = 0.01 mm`
Zero error = `-(50 - 48) xx 0. 01 mm = -0. 02` mm
Measured thickness `= 1 mm + 6 xx 0.01 mm = 1.06 mm`
Actual thickness `= 1. 06 mm - (-0. 02 mm) = 1. 08 mm`