Strength of Materials (Stresses & Strains)

Q.1. The work done on a unit volume of material, as simple tensile force is gradually increased from zero to a value causing rupture, is called
(a) modulus of elasticity
(b) modulus of toughness
(c) modulus of resilience
(d) none of these

Q.2. The unit of modulus of resilience is
(a) N-m^-2
(b) Nm-m^-3
(c) N-m^-3
(d) none of these

Q.3. For most metals, Poisson’s ratio lies in the range
(a) 0.1 to 0.9
(b) 0.05 to 0.1
(c) 1 to 10
(d) 0.25 to 0.35

Q.4. If a material contains same elastic properties in all directions at any point of the body then it is called
(a) anisotropic
(b) orthotropic
(c) isotropic
(d) none of these

Q.5. The stress level below which a material has a high probability of not failure under reversal of stress, is known as
(a) elastic limit
(b) endurance limit
(c) proportional limit
(d) tolerance limit (IES 1995)

Q.6. In fatigue of metals, the endurance limit is
(a) less than yield stress
(b) more than yield stress
(c) equal to ultimate stress in a static test
(d) none of these (AMIE Winter 1996)

Q.7. A steel cable of 2 cm diameter is used to lift a load of 500 kg. Given that, E = 2 x 106 kg/cm2 and the length of the cable is 10 m. Elongation of the cable due to the load will be
(a) 0.5 cm
(b) 0.25 cm
(c) 1 cm
(d) 2/ cm (IES 1993)

Q.8. A mild steel bar is in two parts having equal lengths. The area of cross section of Part I is double that of Part II. If the bar carries an axial load P, then the ratio of elongation in Part I to that in Part II will be
(a) 2
(b) 4
(c) 1/2
(d) 1/4

Q.9. A bar of circular cross section varies uniformly from a cross section 2D to D. If extension of the bar is calculated treating it as a bar of average diameter, then the percentage error will be
(a) 10
(b) 25
(c) 33.33
(d) 50 (IES 1996)

Q.10. A bar of length L and constant cross section(A) is hanging vertically. What would be total increase in length due to self weight(W)?
(a) WL/AE
(b) 2WL/AE
(c) WL/2AE
(d) none of these

1. b
2. b
3. d
4. c
5. b
6. c
7. b
8. c
9. a
10. c