MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 12 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. |
Which of the following can be used to calculate surface energy of a solid? |
| A. | Bond making model |
| B. | Bond breaking model |
| C. | Solid bond theory |
| D. | Interface creation model |
| Answer» C. Solid bond theory | |
| 2. |
In case of coherent interface elastic energy associated with the interface along with the interfacial energy determines its_______ |
| A. | Enthalpy |
| B. | Equilibrium |
| C. | Size |
| D. | Surface tension |
| Answer» C. Size | |
| 3. |
In a typical fluid-vapor interface, the interfacial excess free energy is same as ________ |
| A. | Internal energy |
| B. | Surface tension |
| C. | Kinetic energy |
| D. | Enthalpy |
| Answer» C. Kinetic energy | |
| 4. |
In the equation dG = A*dᵞ+ ᵞ*dA, if dᵞ = 0, what does that mean? (ᵞ is the interfacial free energy, A is the area of interface). |
| A. | The interfacial excess free energy is less than surface tension |
| B. | The interfacial excess free energy is same as surface tension |
| C. | The interfacial excess free energy is greater than surface tension |
| D. | Cannot be predicted |
| E. | .a) The interfacial excess free energy is less than surface tensionb) The interfacial excess free energy is same as surface tensionc) The interfacial excess free energy is greater than surface tensiond) Cannot be predicted |
| Answer» C. The interfacial excess free energy is greater than surface tension | |
| 5. |
Which among the following has the typical energy (J/m2) in the order 10-1? |
| A. | Coincident site lattice boundary |
| B. | Anti-phase boundary |
| C. | Solidification front |
| D. | Twin boundary |
| Answer» D. Twin boundary | |
| 6. |
The anisotropy in crystalline solid is prominent at ___ |
| A. | Lower temperature |
| B. | Higher temperature |
| C. | Zero degree Celsius |
| D. | Cannot be predicted |
| Answer» B. Higher temperature | |
| 7. |
Solids are much more viscous than liquid films and there is transfer of atoms from the bulk to the surface. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 8. |
Interfacial free energy is anisotropic in crystalline solids? |
| A. | True |
| B. | False |
| Answer» B. False | |
| 9. |
What is the order of interfacial free energy found in Grain Boundary? |
| A. | 10-1 |
| B. | 10-2 |
| C. | 10-0 |
| D. | 10-6 |
| Answer» B. 10-2 | |
| 10. |
In the case of a liquid film which of the following is true? (Where ᵞ is the interfacial free energy and A is the area of the interface).a) (dᵞ/dA) > 0b) (dᵞ/dA) < 0c) (dᵞ/d |
| A. | (dᵞ/dA) > 0 |
| B. | (dᵞ/dA) < 0 |
| C. | (dᵞ/dA) = 0 |
| D. | Cannot be predicted |
| E. | .a) (dᵞ/dA) > 0b) (dᵞ/dA) < 0c) (dᵞ/dA) = 0d) Cannot be predicted |
| Answer» D. Cannot be predicted | |
| 11. |
Consider for simplicity a wire frame suspending a liquid film. If one bar of the frame is movable it is found that a force 5N per unit length must be applied to maintain the bar in position. If this force moves a small distance so that the total area of the film is increased by 0.5m2. Interfacial free energy per unit area is given as 4 J/m2. Calculate the change in interfacial energy? (Take the area of interface as 2m2) |
| A. | 0.25 J |
| B. | 0.50 J |
| C. | 8J |
| D. | 0.90 J |
| Answer» D. 0.90 J | |
| 12. |
The free energy of a system containing an interface of area 5mm2 and free energy 6 KJ/mol*mm2 per unit area is given by_______(G’= 10 KJ/mol, is the free energy of the system assuming that all material in the system has the properties of the bulk). |
| A. | 40 KJ/mol |
| B. | 50 KJ/mol |
| C. | 20 KJ/mol |
| D. | 10 KJ/mol |
| Answer» B. 50 KJ/mol | |