Mechanical Metallurgy Mock Test 1

10%

Question 1 of 10

1. What does σ_ij represent in a 3x3 stress matrix?

Stress is applied on i face of the material in the +ve j direction

Stress is applied on i face of the material in the -ve j direction

Stress is applied on j face of the material in the -ve i direction

Stress is applied on j face of the material in the +ve i direction

Question 1 of 10

Question 2 of 10

2. The variation of interatomic energy with atomic distance is given by the following equation V(r)=4ε[(σ/r¹²)−(σ/r⁶)]
Where V(r) is the potential energy, and r is interatomic distance. ε and σ are constant.
Find the value of energy at the point where the interatomic force is zero?

- ε

Question 2 of 10

Question 3 of 10

3. Which of the following statement is NOT correct?

The maximum and minimum values of the normal stress and the shear stress occurs at an angle 90 degree from each other

The variation of shear stress and normal stress occurs is in the form of a sine wave with a period equal to 90 degrees

The sum of the normal stresses on two perpendicular planes is an invariant quantity

The maximum and minimum values of normal stresses on an oblique plane at point P occurs when the shear stress is zero

Question 3 of 10

Question 4 of 10

4. Dilation of the mechanical body is ____________

change in the area of the body

change in the length of the body

change in the volume of the body

change in the width of the body

Question 4 of 10

Question 5 of 10

5. Elastic strain energy per unit volume or strain energy density is NOT equal to ________
Where σx=stress in x direction, εx=strain in x direction, E=young’s modulus, P=load, Δ=elongation.

\(\frac{1}{E}(\sigma x^2)\)

\(\frac{1}{2}(\sigma x\epsilon x)\)

\(\frac{1}{2}(E\epsilon x^2)\)

\(\frac{1}{2}(p \Delta)\)

Question 5 of 10

Question 6 of 10

6. The elastic constant of a material is determined by the ________________ of potential energy vs interatomic distance curve.

curvature

x-intercept

minimum

slope

Question 6 of 10

Question 7 of 10

7. The X and Y- axis of Mohr’s circle represent ________

shear stress and normal stress

principal normal stress and principal shear stress

normal stress and shear stress

principal shear stress and principal normal stress

Question 7 of 10

Question 8 of 10

8. The stress concentration is generally expressed by a theoretical stress-concentration factor k_t. Generally, K_t is described as the ratio of _________________

σ_nominal/σ_max

σ_max / σ_min

σ_max/σ_nominal

σ_min/ σ_max

Question 8 of 10

Question 9 of 10

9. In the stress-strain curve, loading and unloading of the material in the elastic region follow the same path.

False

True

Question 9 of 10

Question 10 of 10

10. Von-mises or Distortion-energy Criteria proposed that yielding will occur when the second invariant of the stress deviator J₂ exceeds some critical value. The second invariant of the stress deviator J₂ is equal to __________

1/2 [(σ₁ - σ₂)²+(σ₂ - σ₃)²+(σ₃ - σ₁)²]

1/6 [(σ₁ - σ₂)²+(σ₂ - σ₃)²+(σ₃ - σ₁)²]

1/2 [(σ₁ - σ₂)+(σ₂ - σ₃)+(σ₃ - σ₁)]

[σ₁ + σ₂ + σ₃]

Question 10 of 10