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MCQOPTIONS
This section includes 427 Mcqs, each offering curated multiple-choice questions to sharpen your Materials Science knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Engineering strain of a mild steel sample is recorded as 0.100%. The true strain is |
| A. | 0.010% |
| B. | 0.055% |
| C. | 0.099% |
| D. | 0.101% |
| Answer» D. 0.101% | |
| 52. |
A mild steel bar is in two parts having equal length. The area of cross-section of part-1 is double that of part-2. If the bar carries an axial load P, then the ratio of elongation in part-1 to that in part-2 will be |
| A. | 2 |
| B. | 4 |
| C. | 1/2 |
| D. | 1/4 |
| Answer» D. 1/4 | |
| 53. |
If the length of a copper plate is 10 mm and this length is increased to 15 mm after an expansion under the tensile load of 50 N. The engineering strain developed in the plate is: |
| A. | 0.2 |
| B. | 2 |
| C. | 0.5 |
| D. | 5 |
| Answer» D. 5 | |
| 54. |
A member which is subjected to reversible tensile or compressive stresses may fail at stresses may fail at stresses lower than the ultimate stresses of the material. This property of metal is called |
| A. | Plasticity of the metal |
| B. | Workability of the metal |
| C. | Fatigue of the metal |
| D. | Creep of metal |
| Answer» D. Creep of metal | |
| 55. |
A steel bar ABC of uniform cross-section 100 mm2 is suspended vertically and loaded as shown in the figure. If the lower end of bar C does not move when loads are applied (neglect self-weight), then the value of force P is (Es = 200 kN/mm2) |
| A. | 24 kN |
| B. | 42 kN |
| C. | 36 kN |
| D. | 15 kN |
| Answer» B. 42 kN | |
| 56. |
A column of rectangular cross-section d units × 1 unit at top is subjected to a load P in addition to its self weight. Then the profile for uniform stress along its length is (ρ = density, σ = stress) |
| A. | \({\rm{d}}{{\rm{e}}^{\left( {\frac{{{\rm{\rho x}}}}{{\rm{\sigma }}}} \right)}}\) |
| B. | \({\rm{d}}{{\rm{e}}^{\left( {\frac{{\rm{\sigma }}}{{{\rm{\rho x}}}}} \right)}}\) |
| C. | \({\rm{d}}{{\rm{e}}^{\left( {\frac{{\rm{x}}}{{\rm{\sigma }}}} \right)}}\) |
| D. | \({\rm{d}}{{\rm{e}}^{\left( {\frac{{\rm{\rho }}}{{\rm{\sigma }}}} \right)}}\) |
| Answer» B. \({\rm{d}}{{\rm{e}}^{\left( {\frac{{\rm{\sigma }}}{{{\rm{\rho x}}}}} \right)}}\) | |
| 57. |
A composite bar made of copper and steel is heated to 120°C from room temperature. If αc > αs, the stress induced in copper bar is: |
| A. | Shear stress |
| B. | Compressive stress |
| C. | No stress |
| D. | Tensile stress |
| Answer» C. No stress | |
| 58. |
Mohr’s circle is drawn for1. a point2. a square block3. a rectangular block4. isotropic materialThe correct answer is |
| A. | 1, 2 and 4 |
| B. | 2 and 4 |
| C. | 1 and 4 |
| D. | 2, 3 and 4 |
| Answer» D. 2, 3 and 4 | |
| 59. |
A rod of copper originally 305 mm long is pulled in tension with a stress of 276 MPa. if the modulus of elasticity is 110 GPa and the deformation is entirely elastic, the resultant elongation will be nearly |
| A. | 1.0 mm |
| B. | 0.8 mm |
| C. | 0.6 mm |
| D. | 0.4 mm |
| Answer» C. 0.6 mm | |
| 60. |
Izod and Charpy test is used to measure _____ of the material. |
| A. | Tensile strength |
| B. | Compressive strength |
| C. | Hardness |
| D. | Toughness or Impact strength |
| Answer» E. | |
| 61. |
Along the principal plane subjected to maximum principal stresses |
| A. | Maximum shear stress acts |
| B. | Minimum shear stress acts |
| C. | No shear stress acts |
| D. | Partial shear stress acts |
| Answer» D. Partial shear stress acts | |
| 62. |
A steel bar of 20 mm × 20 mm square cross-section is subjected to an axial compressive load of 200 kN. If the length of the bar is 1 m and E = 100 GPa, the elongation of the bar will be |
| A. | 0.2 mm |
| B. | 5 mm |
| C. | 2.5 mm |
| D. | 0.5 m |
| Answer» C. 2.5 mm | |
| 63. |
Principal stresses at a point in a plane stressed element are σx = σy = 500 N/mm2. Normal stress on the plane inclined at 45° to the x-axis will be |
| A. | Zero |
| B. | 500 N/mm2 |
| C. | 1000 N/mm2 |
| D. | 707 N/mm2 |
| Answer» C. 1000 N/mm2 | |
| 64. |
In a two-dimensional stress analysis, the state of stress at a point P is\(\left[ \sigma \right] = \left[ {\begin{array}{*{20}{c}} {{\sigma _{xx}}}&{{\tau _{xy}}}\\ {{\tau _{xy}}}&{{\sigma _{yy}}} \end{array}} \right]\)The necessary and sufficient condition for existence of the state of pure shear the point P, is |
| A. | \({\sigma _{xx}}{\sigma _{yy}} - \tau _{xy}^2 = 0\) |
| B. | Τxy = 0 |
| C. | σxx + σyy = 0 |
| D. | \({\left( {{\sigma _{xx}} - {\sigma _{yy}}} \right)^2} + 4\tau _{xy}^2 = 0\) |
| Answer» D. \({\left( {{\sigma _{xx}} - {\sigma _{yy}}} \right)^2} + 4\tau _{xy}^2 = 0\) | |
| 65. |
A steel bar having cross sectional area of 100 π mm2 is subjected to a tensile force of 40 kN. Determine the tensile stress. |
| A. | 127.33 MPa |
| B. | 150 MPa |
| C. | 175.25 MPa |
| D. | 200.05 MPa |
| E. | 160 MPa |
| Answer» B. 150 MPa | |
| 66. |
A 200 × 100 × 50 mm steel block is subjected to a hydrostatic pressure of 15 MPa. The Young’s modulus and Poisson’s ratio of the material are 200 GPa and 0.3 respectively. The change in the volume of the block in mm3 is |
| A. | 85 |
| B. | 90 |
| C. | 100 |
| D. | 110 |
| Answer» C. 100 | |
| 67. |
A system under biaxial loading induces principal stresses of 100 N/cm2 tensile and 50 N/cm2 compressive at a point. The normal stress at that point on the maximum shear stress plane is |
| A. | 75 N/cm2 tensile |
| B. | 50 N/cm2 compressive |
| C. | 100 N/cm2 tensile |
| D. | 25 N/cm2 tensile |
| Answer» E. | |
| 68. |
A tie bar 50 mm × 8 mm is to carry a load of 80 kN. A specimen of the same quality steel of cross-sectional area is 250 mm2. For a maximum load of 125 kN carried by the specimen, the factor of safety in the design will be |
| A. | 3 |
| B. | 2.5 |
| C. | 2 |
| D. | 1.5 |
| Answer» C. 2 | |
| 69. |
A solid steel cube constrained on all six faces is heated so that the temperature rises uniformly by ΔT. If the thermal coefficient of the material is α, Young’s modulus is E and the Poisson’s ratio is v, the thermal stress developed in the cube due to heating is |
| A. | \(-\frac{{\alpha \left( {{\rm{\Delta }}T} \right)E}}{{\left( {1 - 2v} \right)}}\) |
| B. | \(- \frac{{2\alpha \left( {{\rm{\Delta }}T} \right)E}}{{\left( {1 - 2v} \right)}}\) |
| C. | \(- \frac{{3\alpha \left( {{\rm{\Delta }}T} \right)E}}{{\left( {1 - 2v} \right)}}\) |
| D. | \(-\frac{{\alpha \left( {{\rm{\Delta }}T} \right)E}}{{3\left( {1 - 2v} \right)}}\) |
| Answer» B. \(- \frac{{2\alpha \left( {{\rm{\Delta }}T} \right)E}}{{\left( {1 - 2v} \right)}}\) | |
| 70. |
An elastic material of Young’s modulus E and Poisson’s ratio ν is subjected to a compressive stress of σ1 in the longitudinal direction. Suitable lateral compressive stress σ2 are also applied along the other two lateral directions to limit the net strain in each of lateral directions to half of the magnitude that would be under σ1 acting alone. The magnitude of σ2 is |
| A. | \(\frac {\nu}{2(1+\nu)} \sigma_1\) |
| B. | \(\frac {\nu}{2(1-\nu)} \sigma_1\) |
| C. | \(\frac {\nu}{(1+\nu)} \sigma_1\) |
| D. | \(\frac {\nu}{(1-\nu)} \sigma_1\) |
| Answer» C. \(\frac {\nu}{(1+\nu)} \sigma_1\) | |
| 71. |
A metal piece under the stress state of three principal stresses 30, 10 and 5 kg/mm2 is undergoing plastic deformation. The principal strain rates will be in the proportions of |
| A. | 15, -5 and -10 |
| B. | -15, 5 and -10 |
| C. | 15, 5 and 10 |
| D. | -15, -5 and 10 |
| Answer» B. -15, 5 and -10 | |
| 72. |
Rails are laid such that there will be no stress in them at 24°C. If the rails are 32 m long with an expansion allowance of 8 mm per rail, coefficient of linear expansion a = 11´10–6/°C and E = 205 GPa, the stress in the rails at 80°C will be nearly |
| A. | 68 MPa |
| B. | 75 MPa |
| C. | 83 MPa |
| D. | 90 MPa |
| Answer» C. 83 MPa | |
| 73. |
A plane element is subjected to shearing stresses of 50 MPa. The principal stresses existing in this element and the directions of the planes on which they occur would be _______ at __________ respectively. |
| A. | 50 MPa at 45° |
| B. | 50 MPa at 90° |
| C. | 7 MPa at 45° |
| D. | 7 MPa at 90° |
| Answer» B. 50 MPa at 90° | |
| 74. |
Materials become harder due to strain hardening. Strain hardening in case of steel occurs |
| A. | Between yield strength and ultimate strength |
| B. | Between limit of proportionality and yield strength |
| C. | Between ultimate strength and fracture point |
| D. | Below limit of proportionality |
| Answer» B. Between limit of proportionality and yield strength | |
| 75. |
A bar of uniform rectangular section of area A is subjected to an axial tensile load P; it's Young's modulus is E and its Poisson's ratio is 1/m. Its volumetric strain ev is |
| A. | \(\frac{P}{{AE}}\;\left( {1 + \frac{3}{m}} \right)\) |
| B. | \(\frac{P}{{AE}}\left( {1 + \frac{2}{m}} \right)\) |
| C. | \(\frac{P}{{AE}}\left( {1 - \frac{2}{m}} \right)\) |
| D. | \(\frac{P}{{AE}}\left( {1 - \frac{1}{{2m}}} \right)\) |
| Answer» D. \(\frac{P}{{AE}}\left( {1 - \frac{1}{{2m}}} \right)\) | |
| 76. |
For the plane stress situation shown in the figure, the maximum shear stress and the plane on which it acts are: |
| A. | –50 MPa, on a plane 450 clockwise w.r.t. x-axis |
| B. | –50 MPa, on a plane 450 anti-clockwise w.r.t. x-axis |
| C. | 50 MPa, at all orientations |
| D. | Zero, at all orientations |
| Answer» E. | |
| 77. |
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 |
| Answer» D. tube is under tension and rod is under compression | |
| 78. |
A rigid beam of negligible weight is supported in a horizontal position by two rods of steel and copper, 2 m and 1 m long having values of cross-sectional area 1 cm2 and 2 cm2 and E of 200 GPa and 100 GPa respectively. A load is applied as shown in the figure below.If the rigid beam is to remain horizontal, then |
| A. | the forces on both sides should be equal |
| B. | The force on coper rod should be twice the force on steel |
| C. | The force on the steel rod should be twice the force on copper |
| D. | The force P must be applied at the centre of the beam |
| Answer» C. The force on the steel rod should be twice the force on copper | |
| 79. |
A steel rod of original length 200 mm and final length of 200.2 mm after application of an axial tensile load of 20 kN, what will be the strain developed in the rod? |
| A. | 0.01 |
| B. | 0.1 |
| C. | 0.001 |
| D. | 0.0001 |
| Answer» D. 0.0001 | |
| 80. |
A bar of a uniform cross-section of 400 mm2 is loaded as shown in figure below. The stress at section 1-1 is - |
| A. | 125 N/mm2 |
| B. | 50 N/mm2 |
| C. | 100 N/mm2 |
| D. | 200 N/mm2 |
| Answer» C. 100 N/mm2 | |
| 81. |
A metal flat, 40 mm wide 10 mm thick section and 2 m length, is under an axial compressive load of 40 kN. If contraction in length is 1 mm and the increase in width is 0.006 mm, What is the value of Poisson’s ratio? |
| A. | 0.06 |
| B. | 0.3 |
| C. | 0.1 |
| D. | 0.4 |
| Answer» C. 0.1 | |
| 82. |
A 1.25 cm diameter steel bar is subjected to a load of 2500 kg. The stress induced in the bar will be |
| A. | 200 MPa |
| B. | 210 MPa |
| C. | 220 MPa |
| D. | 230 MPa |
| Answer» B. 210 MPa | |
| 83. |
A point in two dimensional stress state subjected to biaxial stress is shown in figure below. What is the normal stress acting on the plane AB inclined at an angle of θ with the vertical plane ? |
| A. | σ cos2 θ |
| B. | σ |
| C. | σ sin θ cos θ |
| D. | zero |
| Answer» C. σ sin θ cos θ | |
| 84. |
Percentage reduction of area in performing tensile test on cast iron may be of the order of:- |
| A. | 50% |
| B. | 25% |
| C. | 0% |
| D. | 15% |
| Answer» D. 15% | |
| 85. |
A square element of a structural part is subjected to biaxial stresses as shown in the figure. On a plane along BD, the intensity of the resultant stress due to these conditions will be |
| A. | 25√5 N/mm2 |
| B. | 50√5 N/mm2 |
| C. | 75√5 N/mm2 |
| D. | 100√5 N/mm2 |
| Answer» E. | |
| 86. |
Choose the INCORRECT conditions for the thermal stress in a body. |
| A. | It is the function of coefficient of thermal expansion. |
| B. | It is the function of temperature rise. |
| C. | It is the function of modulus of elasticity. |
| D. | It is the function of modulus of rigidity. |
| Answer» E. | |
| 87. |
In a material under a state of plane strain, a 10× 10 mm square centred at a point gets deformed as shown in the figure.If the shear strain γxy at this point is expressed as 0.001 k (in rad.) the value of k is |
| A. | 0.5 |
| B. | 0.25 |
| C. | – 0.25 |
| D. | – 0.50 |
| Answer» E. | |
| 88. |
A solid circular shaft of diameter 100 mm is subjected to an axial stress of 50 MPa. It is further subjected to a torque of 10 kNm. The maximum principal stress experienced on the shaft is closest to |
| A. | 41 MPa |
| B. | 82 MPa |
| C. | 164 MPa |
| D. | 204 MPa |
| Answer» C. 164 MPa | |
| 89. |
Mohr’s circle construction is valid for both stresses as well as the area moment of inertia, because |
| A. | both are tensors of first-order |
| B. | both are tensors of second-order |
| C. | both are axial vectors |
| D. | both occur under plane stress condition |
| Answer» C. both are axial vectors | |
| 90. |
A rigid bar with wires at B and C is shown in the figure below. The cross sectional area of the wire at B is 3 × 10-4 m2 and at C is 2 × 10-4 m2. The wires are elasto-plastic with strength 250 MPa & E value 200 GPa. The ultimate load P that can be applied to the rigid bar, as shown is |
| A. | 50 kN |
| B. | 75 kN |
| C. | 100 kN |
| D. | 150 kN |
| Answer» E. | |
| 91. |
A shaft of diameter ‘d’ and length ‘l’ has been loaded axially, the ratio of change in diameter to the original is called __________. |
| A. | Longitudinal strain |
| B. | Shear strain |
| C. | Lateral Strain |
| D. | Volumetric strain |
| Answer» D. Volumetric strain | |
| 92. |
In the case of an engineering material under unidirectional stress in the x-axis, the Poisson’s ratio is equal to (symbols have their usual meanings) |
| A. | εy/εx |
| B. | εy/σx |
| C. | εy/σs |
| D. | σy/εx |
| Answer» B. εy/σx | |
| 93. |
A mild steel bar, circular in cross-section, tapers from 40 mm diameter to 20 mm diameter over its length of 800 mm. It is subjected to an axial pull of 20 kN. E = 2 × 105 N/mm2. The increase in the length of the rod will be |
| A. | \(\frac{1}{{10\pi }}\;mm\) |
| B. | \(\frac{2}{{5\pi }}\;mm\) |
| C. | \(\frac{4}{{5\pi }}\;mm\) |
| D. | \(\frac{1}{{5\pi }}\;mm\) |
| Answer» C. \(\frac{4}{{5\pi }}\;mm\) | |
| 94. |
Member CD of the assembly shown is an aluminium bar 0.80 meter long. Cross-sectional dimension of the bar is such that, its width is three times its thickness. For functional design of the bar CD, the allowable axial stress is 70 MPa, and the total elongation is not to exceed 0.72 mm. E value for aluminium is 70 GPa. Assume the connection at C does not reduce the net area of the bar. The thickness of the bar in metre is |
| A. | \(\frac{2}{{\sqrt {21 \times {{10}^5}} }}~m\) |
| B. | \(\frac{5}{{\sqrt {21 \times {{10}^3}} }}~m\) |
| C. | \(\frac{2}{{\sqrt {21 \times {{10}^3}} }}~m\) |
| D. | \(\frac{3}{{\sqrt {21 \times {{10}^3}} }}~m\) |
| Answer» D. \(\frac{3}{{\sqrt {21 \times {{10}^3}} }}~m\) | |
| 95. |
According to Hookes law stress is proportional to |
| A. | Pressure |
| B. | Strain |
| C. | Elasticity |
| D. | Ductility |
| Answer» C. Elasticity | |
| 96. |
Match the followingA. Youngs modulus1. Shear strainB. Modulus of rigidity2. Normal strainC. Bulk modulus3. Transverse strainD. Poisson’s ratio4. Volumetric strain |
| A. | A – 1, B – 2, C – 3, D - 4 |
| B. | A – 2, B – 1, C – 3, D - 4 |
| C. | A – 2, B – 1, C – 4, D - 3 |
| D. | A – 1, B – 2, C – 4, D - 3 |
| Answer» D. A – 1, B – 2, C – 4, D - 3 | |
| 97. |
A prismatic bar, as shown in figure is supported between rigid supports. The support reactions will be |
| A. | \({R_A} = \frac{{10}}{3}kN\;and\;{R_B} = \frac{{20}}{3}kN\) |
| B. | \({R_A} = \frac{{20}}{3}kN\;and\;{R_B} = \frac{{10}}{3}kN\) |
| C. | RA= 10 kN and RB = 10 kN |
| D. | RA = 5 kN and RB = 5 kN |
| Answer» C. RA= 10 kN and RB = 10 kN | |
| 98. |
A steel bar 2 m long, 20 mm wide and 15 mm thick is subjected to a tensile load of 30 kN. If Poisson’s ratio is 0.25 and Young’s modulus is 200 GPa, an increase in volume will be |
| A. | 160 mm3 |
| B. | 150 mm3 |
| C. | 140 mm3 |
| D. | 130 mm3 |
| Answer» C. 140 mm3 | |
| 99. |
As compared with the conventional stress-strain curve, the true stress-strain curve is |
| A. | Above and right |
| B. | Below and right |
| C. | Above and left |
| D. | Below and left |
| Answer» B. Below and right | |
| 100. |
A steel rod whose diameter is 2 cm and is 2 m long, experiences heating from 30°C to 150°C. The coefficient of thermal expansion is α = 12 × 10-6/°C and the rod has been restricted in its original position. The thermal stress developed is 288 MPa. What is the value of Young’s modulus (GPa)? |
| A. | 50 |
| B. | 100 |
| C. | 150 |
| D. | 200 |
| Answer» E. | |