Modulus of Rigidity MCQ – Strength of Materials

1. Modulus of Rigidity is

  1. axial stress divided by axial strain
  2. shear stress divided by shear strain
  3. increase or decrease in volume divided by original volume
  4. direct stress divided by volumetric strain
Answer
Answer. b

2. Young’s modulus of elasticity and Poisson’s ratio of a material are 1.25 × 105 MPa and 0.34 respectively. The modulus of rigidity of the material is

  1. 0.4025 × 105 MPa
  2. 0.4664 × 105 MPa
  3. 0.8375 × 105 MPa
  4. 0.9469 × 105 MPa
Answer
Answer. b

3. The ratio of Young’s modulus to modulus of rigidity for a material having Poisson’s ratio 0.2 is

  1. 12/5
  2. 5/12
  3. 5/14
  4. 14/5
Answer
Answer. b

4. Which of the following is the correct relation between the modulus of rigidity (C), Young’s modulus of elasticity (E) and bulk modulus (K)?

  1. E = (3CK)/(9K+C)
  2. C = (9EK)/(3K+E)
  3. K = (9EC)/(9C+E)
  4. E = (9CK)/(3K+C)
Answer
Answer. d

5. A material has a Young’s Modulus of 1.25 × 105 N/mm2 and a Poisson’s ratio of 0.25. The Modulus of Rigidity is

  1. 0.65 × 105 N/mm2
  2. 0.60 × 105 N/mm2
  3. 0.45 × 105 N/mm2
  4. 0.50 × 105 N/mm2
Answer
Answer. d

6. A bar 40 mm in diameter and subjected to a 40,000 kg undergoes  elongation resulting in decrease in diameter considering the properties of the material as E = 2 × 105 N/mm2 and Poisson’s ratio as 0.3, the modulus of rigidity will be

  1. 76923.07 N/mm2
  2. 56898.50 N/mm2
  3. 20 × 104 Kg/cm2
  4. 3 × 105 Kg/cm2
Answer
Answer. a

7. The young’s modulus of a material is 150 GPa and Poisson’s ratio is 0.25, the modulus of rigidity of the material is

  1. 50 GPa
  2. 30 GPa
  3. 100 GPa
  4. 60 GPa
Answer
Answer. d

8. The ratio of modulus of rigidity and modulus of elasticity (G/E) for any elastic isotropic material is

  1. less than 1/2
  2. less than 1/3
  3. more than 1/3
  4. both (a) and (c)
Answer
Answer. d

9. The Poisson’s ratio of a material is 0.3 and Young’s modulus is 200 GPa. Its Rigidity Modulus is

  1. 77 GPa
  2. 51 GPa
  3. 125 GPa
  4. 333 GPa
Answer
Answer. a

10. Modulus of rigidity is the ratio of

  1. Linear stress to linear strain
  2. Linear stress to lateral stress
  3. Volumetric strain to linear strain
  4. Shear stress to shear strain
Answer
Answer. d

11. Modulus of Rigidity G can be expressed in usual notations as

  1. E/2(1+μ)
  2. E/2(1+2μ)
  3. 2E/2(1+μ)
  4. 2E/2(1-μ)
Answer
Answer. a