Question

A screw gauge gives the following reading when used to measure the diameter of a wire.
Main scale reading : 0 mm
Circular scale reading : 52 divisions
Given that 1 mm on main scale corresponds to 100 divisions of the circular scale. The diameter of wire from the above data is :

• A. $0.52cm$
• B. $0.052cm$
• C. $0.026cm$
• D. $0.005cm$

Answer 1

The correct option is B $0.052cm$

Here, pitch of the screw gauge, $p=1mm$

Number of circular divisions, $n=100$

Thus, least count $LC=p/n=1/100=0.01mm=0.001cm$

Diameter of the wire $=MSR+(CSR\times LC)=0+(52\times 0.001cm)=0.052cm$