MCQOPTIONS
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MCQOPTIONS
This section includes 13 Mcqs, each offering curated multiple-choice questions to sharpen your Phase Transformation knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
When the boundary moves the solute atoms migrate along with the boundary and exert a drag that reduces the boundary velocity. The magnitude of the drag will depend on ______ |
| A. | Shape of the boundary |
| B. | Texture |
| C. | Concentration in the boundary |
| D. | It is an independent property |
| Answer» D. It is an independent property | |
| 2. |
A recrystallization texture is sometimes an advantage. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3. |
Which among the following is the property of a low angle boundary? |
| A. | Areas of poor fit |
| B. | Relatively open structure |
| C. | Highly disordered |
| D. | Areas of perfect fit |
| Answer» E. | |
| 4. |
When α > 10-15° the boundary is known as a_______ (“α” is the angular misorientation across the boundary) |
| A. | Random high-angle grain boundary |
| B. | Random low-angle grain boundary |
| C. | Super angle grain boundary |
| D. | Axial grain boundary |
| Answer» B. Random low-angle grain boundary | |
| 5. |
If the tilt boundary is unsymmetrical, dislocations with different Burgers vectors are required to accommodate the misfit. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 6. |
For simple arrays, the spacing of dislocation is given by the formula________ (where b is the Burgers vector of the dislocations and α is the angular misorientation across the boundary) |
| A. | D = b/sinα |
| B. | D = b/cosα |
| C. | D = b*sinα |
| D. | D = b*cosα |
| Answer» B. D = b/cosα | |
| 7. |
“α” is the angular misorientation across the boundary. At very small values of α, the dislocation spacing is very large and the grain boundary energy ꙋ is approximately proportional to the____ |
| A. | Position of dislocation |
| B. | Density of dislocation |
| C. | Type of dislocation |
| D. | Volume of dislocation |
| Answer» C. Type of dislocation | |
| 8. |
In the edge dislocations, the Burger vectors and dislocation line are _________ |
| A. | Parallel to each other |
| B. | Perpendicular to each other |
| C. | Close to each other |
| D. | Far away from each other |
| Answer» C. Close to each other | |
| 9. |
Calculate the magnitude of Burgers vector for the BCC lattice expressed as ½<148>, where 1, 4, 8 are their respective components of Burgers vector and the value of “a’’ is given as 1? |
| A. | 6.5 |
| B. | 4 |
| C. | 5.5 |
| D. | 4.5 |
| Answer» E. | |
| 10. |
Which of the following boundary is related to screw dislocation? |
| A. | Low angle twist boundary |
| B. | High angle tilt boundary |
| C. | High angle cross boundary |
| D. | Low angle tilt boundary |
| Answer» B. High angle tilt boundary | |
| 11. |
Which among the following boundary is an array of parallel edge dislocations? |
| A. | Low angle twist boundary |
| B. | High angle tilt boundary |
| C. | High angle twist boundary |
| D. | Low angle tilt boundary |
| Answer» E. | |
| 12. |
Which of the following boundary occurs when the axis of rotation is parallel to the plane of boundary? |
| A. | Roll in boundary |
| B. | Twist boundary |
| C. | Tilt boundary |
| D. | Roll out boundary |
| Answer» D. Roll out boundary | |
| 13. |
The lattices of any two grains can be made to coincide by ________ |
| A. | Twisting across the plane |
| B. | Twirling about multiple axis |
| C. | Turning in the direction of grain boundary |
| D. | Rotating one of them through a suitable angle about a single axis |
| Answer» E. | |