## Strength of Materials Strength of Materials Questions For Competitive Exams

### U.P.S.C., S.S.C., I.A.S., B.Sc. Engineering, Diploma and various interviews

- The unit of stress in S.I. units is:
**N/mm square, KN/mm square, N/meter square** - Whenever some external system of forces acts on a body, it undergoes some deformation. As the body undergoes some deformation, it sets up some resistance to the deformation. This resistance per unit area to deformation is called:
**Stress** - The unit of strain is:
**No unit** - The deformation per unit length is called:
**Strain** - When a body is subjected to two equal and opposite pushes, as a result of which the body tends to reduce its length, the stress and strain induced is:
**compressive** - Strain is equal to
**Change in Length / Actual Length** - When a body is subjected to two equal and opposite forces, acting tangentially across the resisting section, as a result of which the body tends to shear off across the section, the stress and strain induced is:
**Shear Stress, Shear Strain** - When a body is subjected to two equal and opposite pulls, as a result of which the body tends to extend in length, the stress and strain induced is:
**Tensile Stress, Tensile Strain** - Hooks law holds good up to
**Elastic Limit** - Proportional Limit, Elastic Limit, Yielding and thereafter
**Failure** - The ratio of linear stress to linear strain:
**Modulus of Elasticity** - The ratio of shear stress to shear strain:
**Modulus of Rigidity** - The unit of modulus of elasticity is same as those of
**Pressure, Stress, Modulus of Rigidity** - Whenever a material is loaded within elastic limit, stress is:
**directly proportional to strain** - When a change in length takes place, the strain is known as
**Linear Strain** - The modulus of elasticity for Mild Steel is approximately equal to
**210 KN/mm square** - The change in length due to a tensile or compressive force acting on a body is given by
**PL/AE,**where,**P**is Tensile or compressive force acting on the body,**L**is original length of the body,**A**is Cross-Sectional Area of the body,**E**is Young's modulus of the material of the body - The unit of Young's Modulus is same as that of
**Stress** - Young's Modulus may be defined as the ratio of
**Linear Stress to Linear Strain** - Modulus of Rigidity may be defined as the ratio of:
**Shear Stress to Shear Strain** - Two bars of different materials and same size are subjected to same tensile force. If the bars have unit elongation in the ratio of 2:5, then the ratio of modulus of elasticity of the two materials will be:
**5:2** - The deformation of a bar under its own weight is:
**half**the deformation if the same body is subjected to direct load equal to the weight of the body. - When a bar of length l and diameter d is rigidly fixed at the upper end and hanging freely, then the total elongation produced in the bar due to its own weight is:
**w*l square / 2E**where**W**is weight per unit volume of the bar - The length of a conical bar is l, the diameter of the base is d and weight per unit volume is w. It is fixed at its upper end and hanging freely. The elongation of the bar under the action of its own weight will be:
**w*l square/ 6E** - The elongation of a conical bar under its own weight is:
**one-third**that of the prismatic bar of the same length. - Strain rosettes are used to:
**Measure linear strain** - The extension of a circular bar tapering uniformly from diameter d1 at one end to the diameter d2 at the other end, and subjected to an axial pull of P is given by:
**4*P*l / pie*E* d1*d2** - The extension of a circular bar tapering uniformly from diameter d1 at one end to the diameter d2 at the other end, and subjected to an axial pull of P is:
**equal to**the extension of a circular bar of diameter 'root under d1*d2' subjected to the same load P. - A bar of length L metres extend by l mm under a tensile force of P, the strain produced in the bar is:
**0.001l / L** - The ultimate tensile stress of Mild Steel is:
**More than the ultimate compressive stress** - The shear modulus of most materials with respect to the modulus of elasticity:
**is less than half** - The maximum stress produced in a bar of tapering section is at:
**Smaller End** - A bolt is made a pass through a tube and both of them are tightly fitted with the help of washers and nuts. If the nut is tightened, then:
**bolt is under tension and tube is under compression** - A rod is enclosed centrally in a tube and the assembly is tightened by rigid washers. If the assembly is subjected to a compressive load, then:
**both rod and tube are under compression** - A steel bar of 5 mm is heated from 15-degree celsius to 40-degree Celsius and it is free to expand. The bar will induce:
**No Stress** - When a bar is subjected to a change of temperature and its deformation is prevented, the stress induces in the bar is: T
**hermal Stress**