Strain MCQ – Strength of Materials

1. The ratio of change of dimension of the body to the original dimension is known

  1. Strain
  2. Stress
  3. Force
  4. Pressure
Answer. a

2. The ratio of axial deformation to the original length of the body is known as

  1. Lateral strain
  2. Linear stress
  3. Linear strain
  4. Poisson’s ratio
Answer. c

3. If longitudinal strain is tensile, the lateral strain will be

  1. tensile
  2. compressive
  3. zero
  4. not determined
Answer. b

4. The unit of strain is

  1. N-mm
  2. N/mm
  3. N/
  4. No unit
Answer. d

5. Shear strain γyz is given by

$\\a.\; \frac{\partial u}{\partial x}+\frac{\partial v}{\partial y}\\ b.\; \frac{\partial w}{\partial y}+\frac{\partial v}{\partial z}\\ c.\; \frac{\partial u}{\partial z}+\frac{\partial w}{\partial x}\\ d.\; \frac{\partial v}{\partial x}+\frac{\partial u}{\partial y}$

where u, v and w are the displacement vectors along x, y and z axis respectively.

Answer. b

6. A solid cube is subjected to equal normal forces on all its faces. Volumetric strain will be how many times of the linear strain.

  1. 2
  2. 1
  3. 3
  4. 4
Answer. c

7. Strain resisters are used to

  1. Measure shear strain
  2. Measure volumetric strain
  3. Measure linear strain
  4. Relieve strain
Answer. c

8. The ratio between the change in volume and original volume of the body is called

  1. tensile strain
  2. compressive strain
  3. volumetric strain
  4. shear strain
Answer. c

9. The shearing stress in a piece of structural steel is 100 MPa. If the elastic modulus is 200 GPa and the Poisson’s ratio is 0.25, then the shearing strain γ would be

  1. 0.8 rad
  2. 0.00125 rad
  3. 800
  4. 1.25
Answer. b

10. The material of a rubber balloon has Poison’s ratio of 0.5. If uniform pressure is applied to blow the balloon, the volumetric strain of the material will be

  1. 0.25
  2. 0.50
  3. 0.20
  4. 0.00
Answer. d

11. When the strain in a material increases with time under sustained constant stress, the phenomenon is known as

  1. hysteresis
  2. strain hardening
  3. visco-elasticity
  4. creep
Answer. d

12. The ratio of lateral strain to axial strain of a homogeneous material is known as

  1. Yield ratio
  2. Hooke’s ratio
  3. Poisson’s ratio
  4. Plastic ratio
Answer. c

13. A solid cube is subjected to equal normal forces on all its faces. The volumetric strain will be x-times the linear strain in any of the three axes when

  1. x = 2
  2. x = 1
  3. x = 3
  4. x = 4
Answer. c

14. How much (in %) fracture strain is commonly adopted as border between brittle and ductile materials?

  1. 3.5
  2. 7
  3. 4
  4. 5
Answer. d

15. A member with a cross-section of A and length L is subjected to a force of P. If Young’s Modulus is E, then linear strain will be

  1. PL/AE
  2. PA/LE
  3. P/AE
  4. PE/AL
Answer. c

16. Let the strains produced in length and diameter of the cylindrical rod be α and β respectively. Then the volumetric strain is given by

  1. α + 2β
  2. α + β
  3. α – β
  4. α – 2β
Answer. a

17. If a circular rod having Poisson’s ratio μ is subjected to an axial pull and if the strain is e, then the lateral strain is equal to

  1. -μe
  2. μe
  3. -e/μ
  4. e/μ
Answer. a

18. Volumetric strain of a sphere of diameter increasing from d1 to d2 is equal to

$\\a.\; \frac{d_{2}-d_{1}}{d_{1}}\\ b.\; 3\frac{d_{2}-d_{1}}{d_{1}}\\ c.\; \frac{d_{2}+d_{1}}{2d_{1}}\\ d.\; \frac{d_{2}+d_{1}}{2d_{1}}$

Answer. b

19. Let the strain produced in length and diameter of cylindrical rod be 0.02 and 0.005 respectively. Then the volumetric strain is given by

  1. 0.025
  2. 0.03
  3. 0.01
  4. 0.015
Answer. c

20. When a rectangular bar of length l, breadth b and thickness t is subjected to a pull of p, then volumetric strain is

  1. e(l – 2m)
  2. e(2m – l)
  3. e(l – 2/m)
  4. e(2/m – l)
Answer. c