Stress And Strain(Mechanics Of Materials ) Questions and answers for exam Preparation

Question 1. The Youngs modulus of elasticity of a material is 2.5 times its modulus of rigidity. Then what will be its Poissons ratio?

0.25
0.33
0.50
0.60

Explanation:-

Answer: Option A. -> 0.25
Answer: (a).0.25

Question 2. How many elastic constants does an isotropic, homogeneous and linearly elastic material have?

1
2
3
4

Explanation:-

Answer: Option B. -> 2
Answer: (b).2

Question 3. Which of the following is true if the value of Poisson’s ratio is zero?

The material is rigid
The material is perfectly plastic
The longitudinal strain in the material is infinite
There is no longitudinal strain in the material

Explanation:-

Answer: Option A. -> The material is rigid
Answer: (a).The material is rigid

Question 4. How the elastic constants E and K are related?

E = 2K(1 – 2μ)
E = 3K(1 – 2μ)
E = 2K(1 – μ)
E = K(1 – 2μ)

Explanation:-

Answer: Option B. -> E = 3K(1 – 2μ)
Answer: (b).E = 3K(1 – 2μ)

Question 5. The modulus of rigidity and the modulus of elasticity of a material are 80 GPa and 200 GPa. What will be the Poissons ratio of the material?

0.25
0.30
0.40
0.50

Explanation:-

Answer: Option A. -> 0.25
Answer: (a).0.25

Question 6. If E,G and K have their usual meanings, for an elastic material, then which one of the following be possibly true?

G = 2K
G = K
K = E
G = E = K

Explanation:-

Answer: Option C. -> K = E
Answer: (c).K = E

Question 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?

0.26
0.31
0.47
0.43

Explanation:-

Answer: Option B. -> 0.31
Answer: (b).0.31

Question 8. What is the relationship between the linear elastic properties Youngs modulus, bulk modulus and rigidity modulus?

1/E = 9/k + 3/G
9/E = 3/K + 1/G
3/E = 9/K + 1/G
9/E = 1/K + 3/G

Explanation:-

Answer: Option D. -> 9/E = 1/K + 3/G
Answer: (d).9/E = 1/K + 3/G

Question 9. Which of the relationship between E, G and K is true, where E, G and K have their usual meanings?

E = 9KC / (3K + C)
E = 9KC / (9K + C)
E = 3KC / (9K + C)
E = 3KC / (3K + C)

Explanation:-

Answer: Option A. -> E = 9KC / (3K + C)
Answer: (a).E = 9KC / (3K + C)

Question 10. Consider the following statements:
1. Two-dimensional stresses applied to a thin plater in its own plane represent the plane stress condition.
2. Normal and shear stresses may occur simultaneously on a plane.
3. Under plane stress condition, the strain in the direction perpendicular to the plane is zero.
Which of the above statements are correct?

2 only
1 and 2
2 and 3
1 and 3

Explanation:-

Answer: Option D. -> 1 and 3
Answer: (d).1 and 3