Question 244General Subjects - QMED

The correct answer is B) from the one inch graduation mark. When using a machinist's steel rule, the most accurate measurements are taken from the one inch graduation mark, not the zero end of the scale. This is because the metal end of the rule can flex or bend slightly, affecting the precision of the measurement if taken from the very end. By measuring from the one inch mark, you avoid this potential source of error and get a more reliable reading. The other options are incorrect because: A) the unmarked edge is not calibrated, C) measuring on the narrow edge would not provide a linear scale, and D) using the zero end can introduce measurement error due to the flexible metal.