Q. 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 on the circular scale. The diameter of wire from the above data is
A) $0.52\ cm$
B) $0.052\ cm$
C) $0.026\ cm$
D) $0.005\ cm$
Explanation
Least count of screw gauge $= \frac{1}{100}mm = 0.01\ mm$ Diameter $=$ Divisions on circular scale $\times$ least count $+$ $= 52 \times \frac{1}{100} + 0 = 0.52\ mm$ Diameter $= 0.052\ cm$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.