City Guilds Model Questions Vol1 2021 Engineering Question 5

In the Materials laboratory a cylindrical steel specimen is to be tested for its Young's modulus using a universal testing machine (UTM). The specimen is clamped between the machine grips and the gauge length (distance between the inner faces of the grips) is 200 mm. The diameter of the specimen is measured at three equally spaced locations along its length and the readings are 12.00 mm, 11.96 mm and 12.04 mm. The UTM records the applied axial load and the corresponding extension of the specimen as follows: | Load (kN) | Measured extension (mm) | |-----------|--------------------------| | 5 | 0.15 | | 10 | 0.31 | | 15 | 0.48 | The machine has a compliance of 0.02 mm kN⁻¹, meaning that a portion of the measured extension is due to deformation of the machine itself. Using the data provided, answer the questions below.