Strength of Materials Practice Test 2

1. Two sections in a bar of length 10cm and 20cm respectively are pulled axially. It causes an elongation of 0.2mm and 0.4mm respectively in each section. What will be the resultant strain in the bar?

2. If a bar of sections of two different length and different diameters are in a line and P load is acting axially on them then what will be the change in length of the bar?

3. A bar is subjected to a tensile load of 150kN. If the stress in the middle portion is limited to 160 N/mm², what will be the diameter of the middle portion of the total elongation of the bar is 0.25cm (E= 2 x 105)?

4. The thermal stress is a function of _____________
P. Coefficient of linear expansion
Q. Modulus of elasticity
R. Temperature rise

5. A tensile load of 60kN is gradually applied to a circular bar of 4cm diameter and 10m long. What will be the strain energy absorbed by the rod if E=1x105 N/mm²?

6. Where will be the center of gravity of the L-section shown in figure?

7. A member ABCD is subjected to points load P₁=45kN, P₂, P₃=450kN and P₄=130kN. what will be the value of P necessary for equilibrium?

8. A composite rod is 1000mm long, its two ends are 40mm² and 30mm² in area and length are 300mm and 200mm respectively. The middle portion of the rod is 20mm² in area. If the rod is subjected to an axial tensile load of 1000N, what will be its total elongation (E = 200GPa)?

9. A material of youngs modulus and Poissons ratio of unity is subjected to two principal stresses σ₁ and σ₂ at a point in two dimensional stress system. The strain energy per unit volume of the material is __________

10. A composite bar having two sections of cross-sectional area 100mm² and 200mm² respectively. The length of both the sections is 100mm. What will be the total elongation of bar if it is subjected to axial force of 100kN and E = 105 N/mm²?