Elastic Constants Relationship MCQ question and answers

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Elastic Constants Relationship MCQ question and answers

1. What is the ratio of Youngs modulus E to shear modulus G in terms of Poissons ratio?
a) 2(1 + μ)
b) 2(1 – μ)
c) 1/2 (1 – μ)
d) 1/2 (1 + μ)
Answer: a).

2. The relationship between Youngs modulus E, bulk modulus K if the value of Poissons ratio is unity will be __________
a) E = -3K
b) K = -3E
c) E = 0
d) K = 0
Answer: a

3. A rod of length L and diameter D is subjected to a tensile load P. which of the following is sufficient to calculate the resulting change in diameter?
a) Youngs modulus
b) Poissons ratio
c) Shear modulus
d) Both Youngs modulus and shear modulus
Answer: a

4. E, G, K and μ elastic modulus, shear modulus, bulk modulus and Poisson’s ratio respectively. To express the stress strain relations completely for this material, at least __________
a) E, G and μmust be known
b) E, K and μmust be known
c) Any two of the four must be known
d) All the four must be known
Answer: c

5. Youngs modulus of elasticity and Poissons ratio of a material are 1.25 x 102 MPa and 0.34 respectively. The modulus of rigidity of the material is __________
a) 0.9469 MPa
b) 0.8375 MPa
c) 0.4664 MPa
d) 0.4025 MPa
Answer: c

6. If E,G and K have their usual meanings, for an elastic material, then which one of the following be possibly true?
a) G = 2K
b) G = K
c) K = E
d) G = E = K
Answer: c

7. If a material had a modulus of elasticity of 2.1 kgf/cm2 and a modulus of rigidity of 0.8 kgf/cm2 then what will be the approximate value of the Poissons ratio?
a) 0.26
b) 0.31
c) 0.47
d) 0.43
Answer: b

8. Consider the following statements:
X. Two-dimensional stresses applied to a thin plater in its own plane represent the plane stress condition.
Y. Normal and shear stresses may occur simultaneously on a plane.
Z. Under plane stress condition, the strain in the direction perpendicular to the plane is zero. Which of the above statements are correct?
a) 2 only
b) 1 and 2
c) 2 and 3
d) 1 and 3
Answer: d

9. What is the relationship between the linear elastic properties Youngs modulus, bulk modulus and rigidity modulus?
a) 1/E = 9/k + 3/G
b) 9/E = 3/K + 1/G
c) 3/E = 9/K + 1/G
d) 9/E = 1/K + 3/G
Answer: d

10. Which of the relationship between E, G and K is true, where E, G and K have their usual meanings?
a) E = 9KC / (3K + C)
b) E = 9KC / (9K + C)
c) E = 3KC / (9K + C)
d) E = 3KC / (3K + C)
Answer: a