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. |
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*d + *dA, if d = 0, what does that mean? ( 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 |
| 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<sup>-1</sup> |
| B. | 10<sup>-2</sup> |
| C. | 10<sup>-0</sup> |
| D. | 10<sup>-6</sup> |
| Answer» B. 10<sup>-2</sup> | |
| 10. |
Why is the value of (d /dA) =0 in case of a liquid film? |
| A. | Liquid is unable to support shear stresses |
| B. | Liquid develops viscous forces |
| C. | Liquid can support shear stresses |
| D. | Intermolecular forces in liquid is quite high |
| Answer» B. Liquid develops viscous forces | |
| 11. |
In the case of a liquid film which of the following is true? (Where is the interfacial free energy and A is the area of the interface). |
| A. | (d /dA) > 0 |
| B. | (d /dA) < 0 |
| C. | (d /dA) = 0 |
| D. | Cannot be predicted |
| Answer» D. Cannot be predicted | |
| 12. |
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 | |
| 13. |
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 | |