In a screw gauge, the zero of main scale coincides with fifth division of circular scale in figure (

Question

In a screw gauge, the zero of main scale coincides with fifth division of circular scale in figure (i). The circular division of screw gauge are 50. It moves 0.5 mm on main scale in one rotation. The diameter of the ball in figure (ii) is\

Professor PC Thomas Classes · Answer

(c) : Least count of screw gauge\ $=\frac{	ext { Pitch }}{n}=\frac{0.5}{50}=0.01 \mathrm{~mm}$\ $	herefore \quad$ Diameter of ball $=(2 	imes 0.5 \mathrm{~mm})$\ $+(25-5) 	imes 0.01 \mathrm{~mm}$\ $=1+(0.01 	imes 20)=1.20 \mathrm{~mm}$.\