GATE CE 2021: STRENGTH OF MATERIAL#1

A steel bar of length 1.7 m having material yield point of 275 MPa and modulus of elasticity of 200 GPa. An applied axial load gradually builds up from zero to a value such that the elongation of the bar is 15 mm after which load is removed. If we assume elastic and perfectly plastic behaviour of the material, then the permanent elongation of the bar after removal of the load is

A cylindrical piece of steel, with a diameter of 60mm and length 100 mm, is subjected to an axial compressive force of 40,000 kg. If bulk modulus is 1.7 x 10⁶ kg/cm² and poisson’s ratio is 0.25 than the change in volume of the cylindrical piece is

A tapered circular rod of diameter varying from 20 mm to 10 mm is connected to another uniform circular rod of diameter 10 mm as shown in the following figure. Both bars are made of same material with the modulus of elasticity, E = 2 × 10⁵ MPa. When subjected to a load P = 30ï kN, the deflection at point A is ___________________ mm.

In an axial tensile test on a 15 mm diameter bar of gauge length 200 mm, the load at proportional limit is found to be 25 kN and the corresponding change in length and diameter are 0.25 mm and 0.00625 mm, respectively. The poisson’s ratio and % volume change, respectively are