Test your basic knowledge |

Engineering Materials

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Occur when lots of dislocations move.






2. Metals are good conductors since their _______is only partially filled.






3. Plastic means permanent! When a small load is applied - bonds stretch & planes shear. Then when the load is no longer applied - the planes are still sheared.






4. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.






5. 1. Diamagnetic (Xm ~ 10^-5) - small and negative magnetic susceptibilities 2. Paramagnetic (Xm ~ 10^-4) - small and positive magnetic susceptibilities 3. Ferromagnetic - large magnetic susceptibilities 4. Ferrimagnetic (Xm as large as 10^6) - large m






6. Occurs at a single pore or other solid by refraction n = 1 for pore (air) n > 1 for the solid - n ~ 1.5 for glass - Scattering effect is maximized by pore/particle size within 400-700 nm range - Reason for Opacity in ceramics - glasses and polymers.






7. The ability of a material to transport heat - Atomic Perspective: Atomic vibrations and free electrons in hotter regions transport energy to cooler regions - Metals have the largest values






8. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe






9. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.






10. Increase temperature - increase in interatomic separation - thermal expansion






11. Width of smallest feature obtainable on Si surface






12. These materials are "attracted" to magnetic fields.






13. Stress concentration at a crack tips






14. Measures Hardness - No major sample damage - Each scales runs to 130 but only useful in range 20-100 - Minor load is 10 kg - Major load: 60 kg (diamond) - 100 kg (1/16 in. ball) - 150 kg (diamond)






15. High toughness; material resists crack propagation.






16. They are used to assess properties of ceramics & glasses.






17. 1. Tensile (opening) 2. Sliding 3. Tearing






18. Defines the ability of a material to resist fracture even when a flaw exists - Directly depends on size of flaw and material properties - K(ic) is a materials constant






19. # of thermally generated electrons = # of holes (broken bonds)






20. Cracks propagate along grain boundaries.






21. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)






22. Another optical property - Depends on the wavelength of the visible spectrum.






23. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid






24. Because of ionic & covalent-type bonding.






25. There is always some statistical distribution of flaws or defects.






26. Without passing a current a continually varying magnetic field will cause a current to flow






27. Hardness is the resistance of a material to deformation by indentation - Useful in quality control - Hardness can provide a qualitative assessment of strength - Hardness cannot be used to quantitatively infer strength or ductility.






28. Process by which metal atoms diffuse because of a potential.






29. 1. Yield = ratio of functional chips to total # of chips - Most yield loss during wafer processing - b/c of complex 2. Reliability - No device has infinite lifetime. Statistical methods to predict expected lifetime - Failure mechanisms: Diffusion reg






30. Diffuse image






31. 1. Ability of the material to absorb energy prior to fracture 2. Short term dynamic stressing - Car collisions - Bullets - Athletic equipment 3. This is different than toughness; energy necessary to push a crack (flaw) through a material 4. Useful in






32. Second phase particles with n > glass.






33. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.






34. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.






35. 1. Fluorescent Lamp - tungstate or silicate coating on inside of tube emits white light due to UV light generated inside the tube. 2. TV screen - emits light as electron beam is scanned back and forth.






36. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.






37. A parallel-plate capacitor involves an insulator - or dielectric - between two metal electrodes. The charge density buildup at the capacitor surface is related to the dielectric constant of the material.






38. Typical loading conditions are _____ enough to break all inter-atomic bonds






39. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.






40. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)






41. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.






42. Dimples on fracture surface correspond to microcavities that initiate crack formation.






43. Increase temperature - no increase in interatomic separation - no thermal expansion






44. Undergo extensive plastic deformation prior to failure.






45. ...occurs in bcc metals but not in fcc metals.






46. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.






47. Loss of image transmission - You get no image - There is no light transmission - and therefore reflects - scatters - or absorbs ALL of it. Both mirrors and carbon black are opaque.






48. For a metal - there is no ______ - only reflection






49. Growth of an oxide layer by the reaction of oxygen with the substrate - Provides dopant masking and device isolation - IC technology uses 1. Thermal grown oxidation (dry) 2. Wet Oxidation 3. Selective Oxidation






50. Specific heat = energy input/(mass*temperature change)