MCQOPTIONS
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MCQOPTIONS
This section includes 15 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. |
The total undercooling at the eutectic front (ΔTo) has two contributions. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 2. |
Under what condition is it possible to solidify an off-eutectic alloy without permitting the formation of the primary dendritic phase? |
| A. | Controlled solidification |
| B. | Rapid solidification |
| C. | Multi-directional solidification |
| D. | No such condition exist |
| Answer» B. Rapid solidification | |
| 3. |
Various different types of eutectic solidification are possible and these are usually classified as____ |
| A. | Normal and anomalous |
| B. | Perfect and Imperfect |
| C. | Proper and Dismantled |
| D. | Even and uneven |
| Answer» B. Perfect and Imperfect | |
| 4. |
In the case of the Al₆Fe-Al rod-like eutectic, the impurity causing the cellular structure is mainly___ |
| A. | Aluminum |
| B. | Ferrous |
| C. | Nickel |
| D. | Copper |
| Answer» E. | |
| 5. |
In general the tendency to form dendrites increases as the solidification range______ |
| A. | Becomes constant |
| B. | Increases |
| C. | Decreases |
| D. | Nothing can be predicted |
| Answer» C. Decreases | |
| 6. |
Which among the following can be categorized as a peritectic reaction? |
| A. | Liquid + α(liquid phase)->β(liquid phase) |
| B. | Liquid + α(solid phase)->β(liquid phase) |
| C. | Liquid + α(liquid phase)->β(solid phase) |
| D. | Liquid + α(solid phase)->β(solid phas |
| E. | ->β(liquid phase)b) Liquid + α(solid phase)->β(liquid phase)c) Liquid + α(liquid phase)->β(solid phase)d) Liquid + α(solid phase)->β(solid phase) |
| Answer» E. ->β(liquid phase)b) Liquid + α(solid phase)->β(liquid phase)c) Liquid + α(liquid phase)->β(solid phase)d) Liquid + α(solid phase)->β(solid phase) | |
| 7. |
Unidirectional solidification has commercial importance. |
| A. | False |
| B. | True |
| Answer» C. | |
| 8. |
As the A-rich α phase solidifies excess B diffuses a short distance laterally where it is incorporated in the B-rich β phase. For an interlamellar spacing K, there is a total of X m2 of α/β interface per m3 of eutectic. Find the value of X? |
| A. | 1/K |
| B. | 3/K |
| C. | 2/K |
| D. | 2/K2 |
| Answer» C. 2/K | |
| 9. |
In practice alloy solidification will usually possess certain features. Actually there is some stirring caused by the turbulence of the liquid which can happen due to many reasons. Which among the following is not a reason for that? |
| A. | Pouring |
| B. | Convection currents |
| C. | Gravity currents |
| D. | Composition of alloy |
| Answer» E. | |
| 10. |
Under the steady state growth of the critical gradient, if we consider T1 and T3 to be the liquidus and solidus temperatures for the bulk composition Xo. The equilibrium freezing range of the alloy solidus can be taken as _______ |
| A. | T3-T1 |
| B. | Xo*(T3-T1) |
| C. | T3/T1 |
| D. | T1-T3 |
| Answer» E. | |
| 11. |
Which among the following equation is related to diffusional mixing in liquid (during steady state)? (Where D, Cl, Cs, v represents the diffusivity in liquids, solute concentration of liquid and solid, constant rate and Cl’=dCl/dx respectively) |
| A. | –DCl = v(Cl-Cs) |
| B. | DCl = (Cl-Cs)/v |
| C. | DCl = Cs-Cl/v |
| D. | DCl = v (Cl-Cs) |
| E. | ? (Where D, Cl, Cs, v represents the diffusivity in liquids, solute concentration of liquid and solid, constant rate and Cl’=dCl/dx respectively)a) –DCl = v(Cl-Cs)b) DCl = (Cl-Cs)/vc) DCl = Cs-Cl/vd) DCl = v (Cl-Cs) |
| Answer» B. DCl = (Cl-Cs)/v | |
| 12. |
When there will be a rapid build-up of solute ahead of the solid and a correspondingly rapid increase in the composition of the solid formed. This is known as ___ |
| A. | Final transient |
| B. | Cover up |
| C. | Random order |
| D. | Initial transient |
| Answer» E. | |
| 13. |
“Non-equilibrium lever rule” is also known by the name _________ |
| A. | Matano analysis |
| B. | Cape theory |
| C. | Dobrienier theory |
| D. | Scheil’s equation |
| Answer» E. | |
| 14. |
If we consider an idealized phase diagram by assuming that the solidus and liquidus are straight lines. Then the partition coefficient can be taken as _____ (Xs and Xl are the mole fractions of solid and liquid respectively) |
| A. | K = (Xl-Xs)/Xs |
| B. | K = (Xl-Xs)/Xl |
| C. | K = Xl/(Xl-Xs) |
| D. | K = Xs/Xl |
| Answer» E. | |
| 15. |
The solidification of pure metals is rarely encountered in practice. Which among the following is a reason for this? |
| A. | Pure metals contain sufficient impurities |
| B. | Pure metals have high value of Tm |
| C. | Pure metals have low melting temperature |
| D. | Pure metals can withstand high pressure |
| Answer» B. Pure metals have high value of Tm | |