MCQOPTIONS
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MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Metallurgy knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If the two flows of different geometry have the same value of K, then the stress field around each of the flow will be identical. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2. |
The Dimension of the stress intensity factor K is __________ |
| A. | MPa m<sup>-1/2</sup> |
| B. | MPa m<sup>1/2</sup> |
| C. | MPa m |
| D. | MPa m<sup>-1</sup> |
| Answer» B. MPa m<sup>1/2</sup> | |
| 3. |
The stress intensity factor for a Sharpe elastic crack in the infinity wide plate is equal to ________ |
| A. | K= ( a) |
| B. | K= ( a) |
| C. | K= ( a)<sup>2</sup> |
| D. | K= ( /a) |
| Answer» B. K= ( a) | |
| 4. |
The stress intensity factor at local crack tip is proportional to __________ |
| A. | length of crack |
| B. | half-length of crack |
| C. | square of half-length of the crack |
| D. | square root of half-length of the crack |
| Answer» E. | |
| 5. |
As the crack length increases, the required load value to extend the crack ______ |
| A. | remains constant |
| B. | increases |
| C. | decreases |
| D. | cannot be determined |
| Answer» D. cannot be determined | |
| 6. |
According to the fracture theory of the material, the critical value of the crack extension force, which makes the crack propagate to the fracture is called the fracture toughness of the material. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 7. |
The unit of crack extension force c is ____________ |
| A. | N m |
| B. | N m<sup>-1</sup> |
| C. | N m<sup>2</sup> |
| D. | N m<sup>-2</sup> |
| Answer» C. N m<sup>2</sup> | |
| 8. |
The fracture stress according to Irwin s modification is given as ________ |
| A. | (E <sub>c</sub>/ a)<sup>1/2</sup> |
| B. | (E <sub>c</sub>/ a) |
| C. | (E <sub>c</sub>/2 a)<sup>1/2</sup> |
| D. | (E <sub>c</sub>/2 a) |
| Answer» B. (E <sub>c</sub>/ a) | |
| 9. |
The young s modulus of the steel is 600 MPa, and the plastic stress required to extend the crack is 50*10-9, and the initial crack length is 2 microns. Find the fracture stress required to crack the material? |
| A. | 15 MPa |
| B. | 50 MPa |
| C. | 15 GPa |
| D. | 10 MPa |
| Answer» B. 50 MPa | |
| 10. |
The fracture stress according to Orowan s theory of brittle fracture is __________ (where E is Yong s modulus, p is the plastic work required to extend the crack wall of the length 2a). |
| A. | (E <sub>p</sub>/a)<sup>1/2</sup> |
| B. | (E <sub>p</sub>/a) |
| C. | (E <sub>p</sub>/2a)<sup>1/2</sup> |
| D. | (E <sub>p</sub>/2a) |
| Answer» B. (E <sub>p</sub>/a) | |