Alignment error in measurement occurs due to improper alignment of the measuring tool.
In the determination of Young’s modulus (Y=4 MLgπl d2) by using Searle’s method, a wire of length L=2m and diameter d=0.5mm is used. For a load M=2.5kg, an extension l=0.25mm in the length of the wire is observed. Quantities d and l are measured using a screw gauge and a micrometer, respectively. They have the same pitch of 0.5mm. The number of divisions on their circular scale is 100. The contributions to the maximum probable error of the Y measurement is: