Question

Q3: When a mild steel rod was tested under tension, it was observed that a load of 8 kN causes an
extension of 0.024 cm in the rod. The maximum load carried by the steel rod was observed to be
20 kN and the load beyond which stress is not proportional to strain was noted as 10 kN. When the
specimen breaks, the elongation in the rod measured was 5.25 cm and the diameter at the fracture
observed was 0.455 cm. What will be the length and diameter of the steel rod if the total
elongation of the steel rod was found to be 25% and the area of contraction at fracture estimated
was 12%? Based on the test results, determine the values for the stress corresponding to limit of
proportionality, modulus of elasticity of the material and the ultimate stress developed due to
tension.
Experiments were conducted on another brass rod having diameter same as that of the steel rod
and the changes in the dimensions were tabulated. Within elastic limit, the extension of the brass
rod is found to be 35% more than that of the steel rod for a length of 18 cm, suggest a suitable
value for the applied load and determine the percentage increase in the values of stress and the
strain? Given modulus of elasticity of brass is equal to 0.88 times that of the modulus of elasticity
of steel. Compare the properties of steel rod and brass rod based on the test results. (8

Answer 1

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