Student $A$ and Student $B$ used two screw gauges of equal pitch and 100 equal circular divisions to

Question

Student $A$ and Student $B$ used two screw gauges of equal pitch and 100 equal circular divisions to measure the radius of a given wire. The actual value of the radius of the wire is 0.322 cm . The absolute value of the difference between the final circular scale readings observed by the students, $A$ and $B$ is ________ .\ [Figure shows position of reference ' $O$ ' when jaws of screw gauge are closed] Given pitch $=0.1 \mathrm{~cm}$.\

Professor PC Thomas Classes · Answer

(13) : For student $A$ : Pitch $=0.1 \mathrm{~cm}$,\ L.C. $=\frac{0.1}{100}=0.001$ Number of divisions on circular scale,\ $N=100$\ The reading is given by\ Reading $=$ MSR + CSR + error\ $0.322=0.3+$ CSR $+5 	imes 0.001$\ CSR $=0.017$\ For student $B: 0.322=0.2+\mathrm{CSR}+0.092$\ CSR $=0.030$\ Difference $=0.030-0.017=0.013 \mathrm{~cm}$\ Division in circular scale $=\frac{0.013}{0.001}=13$\