Important MCQs of SOM | All competitive exams | set 1- Mechanicaltalks

Here are top 20 important MCQs of SOM  (Strength of material). Read the questions carefully and try to answer all of them from your own.

Q1.The unit of stress in S.1. units is

(a) N/mm²
(b) kN/mm²
(c) N/m²
(d) any one of these.

Q2. The deformation per unit length is called
(a) tensile stress
(b) compressive stress
(c) shear stress
(d) strain.

Q3. The unit of strain is
(a) N-mm
(b) N/mm
(c) mm
(d) no unit.

Q4. 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.
(a) True
(b) False

Q5. When a body is subjected to two equal and opposite pulls, as a result of which the body tends to extend its length, the stress and strain induced is
(a) compressive stress, tensile strain
(b) tensile stress.compressive strain
(c) tensile stress, tensile strain
(d) compressive stress, compressive strain.

Q6. 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
(a) tensile stress, tensile strain
(b) compressive stress, compressive strain
(c) shear stress, tensile strain
(d) shear stress, shear strain.

Q7. Which of the following is a proper sequence?
(a) proportional limit, elastic limit, yielding, failure
(b) elastic limit, proportional limit, yielding, failure
(c) yielding, proportional limit, elastic limit, failure.
(d) none of the above.

Q8. Hook’s law holds good up to
(a) yield point
(b) elastic limit
(c) plastic limit
(d) breaking point.

Q9. Whenever a material is loaded within elastic limit, stress is…..strain.
(a) equal to
(b) directly proportional to
(c) inversely proportional to
(d) none of the above.

Q10. The ratio of linear stress to the linear strain is called
(a) modulus of rigidity
(b) bulk modulus
(c) modulus of elasticity
(d) Poisson’s ratio.

Q11. The unit of modulus of elasticity is same as those of
(a) stress, strain and pressure
(b) strain, force and pressure
(c) stress, force and modulus of rigidity
(d) stress, pressure and modulus of rigidity.

Q12. Strain rosetters are used to
(a) measure shear strain
(b) measure linear strain
(c) measure volumetric strain
(d) relieve strain.

Q13. A bar of length L metres extends by /mm under a tensile force of P. The strain produced in the bar is
(a) I /L
(b) 0.1l / L
(c) 0.01l / L
(d) 0.001l / L.

Q14. The extension of a circular bar tapering uniformly from diameter dat one end to diameter d, t the other end, and subjected to an axial pull of P is given by
(a) δl = 4PE / πld^2
(b) δl = 4πld^2 / PE
(c) δl = 4PL / πEd1.d2
(d) δl = 4PLE / πd1.d2

Q15. The extension of a circular bar tapering uniformly from diameter d1, at one end to diameter d2, at the other end, and subjected to an axial pull of P is ___ the extension of a circular bar of diameter √d1.d2 subjected to the same load P.
(a) equal to
(b) less than
(c) greater than.

Q16. The ultimate tensile stress for mild steel is ___ the ultimate compressive stress.
(a) equal to
(b) less than
(c) more than.

Q17. The maximum stress produced in a bar of tapering section is at
(a) smaller end
(b) larger end
(c) middle
(d) anywhere.

Q18. Modular ratio of the two materials is the ratio of
(a) linear stress to linear strain
(b) shear stress to shear strain
(c) their modulus of elasticities
(d) their modulus of rigidities.

Q19. The shear modulus of most materials with respect to the modulus of elasticity is
(a) equal to half
(b) less than half
(c) more than half
(d) none of these.

Q20. 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
(a) rod is under compression
(b) tube is under compression
(c) both rod and tube are under compression
(d) tube is under tension and rod is under compression.

Q21. A bolt is made to pass through a tube and both of them are tightly fitted with the help of washers and nuts. If the nut is tightened, then
(a) bolt and tube are under tension
(b) bolt and tube are under compression
(c) bolt is under compression and tube is under tension
(d) bolt is under tension and tube is under compression.