## 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