Explore topic-wise MCQs in Mechanical Metallurgy Questions and Answers.

This section includes 6 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Metallurgy Questions and Answers knowledge and support exam preparation. Choose a topic below to get started.

1.

Griffith’s theory for a thick plate predicts the fracture as_________

A. \(σ=(\frac{2Eϒ}{(1-v)πc)})^{1/2}\)
B. \(σ=(\frac{2Eϒ}{πc})^{1/2}\)
C. \(σ=(\frac{2Eϒ}{πc})^{1/2}\)
D. \(σ=(\frac{2Eϒ(1-v)}{πc})^{1/2}\)
Answer» B. \(σ=(\frac{2Eϒ}{πc})^{1/2}\)
Discussion
2.

The statement of Griffith theory of brittle fracture says that “A crack will propagate when the decrease in elastic strain energy is at least equal to the energy required to create the new surface”.

A. True
B. false
Answer» B. false
Discussion
3.

Calculate the fracture stress of brittle material with the following properties.

A. E=200GPa, Surface energy=1.2 Jm-2, c=0.5*103nm
B. 346.4 MPa
C. 648.9 MPa
D. 589.9 MPa
E. 5898.8 MPa
Answer» B. 346.4 MPa
Discussion
4.

The fracture on the sharpest crack tip will be equal to \((\frac{Eϒ_s}{4c})^{1/2}\) .

A. True
B. False
Answer» B. False
Discussion
5.

The maximum stress on the tip of the crack of length 2c and radius of curvature of the tip ρt is given as ____

A. σmax=\(σ[1+2(\frac{c}{ρt})^{1/2}]\)
B. σmax=\(σ[1+(\frac{c}{ρt})^{1/2}]\)
C. σmax=\(σ[2(\frac{c}{ρt})^{1/2}]\)
D. σmax=\(σ[(\frac{c}{ρt})^{1/2}]\)
Answer» B. σmax=\(σ[1+(\frac{c}{ρt})^{1/2}]\)
Discussion
6.

Determine the cohesive strength of glass fibre, if E = 90 GPa, Surface energy = 1.2 Jm-1/2 and a0=0.18 nm?

A. 29.5 GPa
B. 10 GPa
C. 24.5 GPa
D. 150 MPa
Answer» D. 150 MPa
Discussion