The basic information, about a given screw gauge, is as follows
(i) Number of divisions on the circular scale = 50
(ii) Distance moved, by the moving jaw, in 5 complete rotations = 5 mm
(iii) Position of the zero of the circular scale, when the two jaws just touch each other; as shown in the figure When a wire is just held between the jaws of the screw gauge
(a) Reading of the main scale = 6.2 mm
(b) No. of circular scale division coinciding with the ‘reference line’ = 38
The radius, of this wire, equals
(1) 0.326 cm
(2) 0.652cm
(3) 0.664 cm
(4) 0.332 cm
