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






2. 1. Ductility- % elongation - % reduction in area - may be of use in metal forming operations (e.g. - stretch forming). This is convenient for mechanical testing - but not very meaningful for most deformation processing. 2. Toughness- Area beneath str






3. Undergo little or no plastic deformation.






4. Emitted light is in phase






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






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






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






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






9. Transformer cores require soft magnetic materials - which are easily magnetized and de-magnetized - and have high electrical resistivity - Energy losses in transformers could be minimized if their cores were fabricated such that the easy magnetizatio






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






11. Rho=F/A - tau=G/A . Depending on what angle the force is applied - and what angle the crystal is at - it takes different amounts of force to induce plastic deformation.






12. Second phase particles with n > glass.






13. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is






14. Measures impact energy 1. Strike a notched sample with an anvil 2. Measure how far the anvil travels following impact 3. Distance traveled is related to energy required to break the sample 4. Very high rate of loading. Makes materials more "brittle."






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






16. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB






17. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.






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






19. Transmitted light distorts electron clouds - The velocity of light in a material is lower than in a vacuum - Adding large ions to glass decreases the speed of light in the glass - Light can be "bent" (or refracted) as it passes through a transparent






20. 1. Tc= critical temperature- if T>Tc not superconducting 2. Jc= critical current density - if J>Jc not superconducting 3. Hc= critical magnetic field - if H > Hc not superconducting






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






22. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow






23. 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






24. The ability of a material to absorb heat - Quantitatively: The energy required to produce a unit rise in temperature for one mole of a material.






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






26. These materials are relatively unaffected by magnetic fields.






27. Cracks pass through grains - often along specific crystal planes.






28. Digitalized data in the form of electrical signals are transferred to and recorded digitally on a magnetic medium (tape or disk) - This transference is accomplished by a recording system that consists of a read/write head - "write" or record data by






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






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






31. Degree of opacity depends on size and number of particles - Opacity of metals is the result of conduction electrons absorbing photons in the visible range.






32. - Metals that exhibit high ductility - exhibit high toughness. Ceramics are very strong - but have low ductility and low toughness - Polymers are very ductile but are not generally very strong in shear (compared to metals and ceramics). They have low






33. A three terminal device that acts like a simple "on-off" switch. (the basis of Integrated Circuits (IC) technology - used in computers - cell phones - automotive control - etc) - If voltage (potential) applied to the "gate" - current flows between th






34. 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






35. Different orientation of cleavage planes in grains.






36. The size of the material changes with a change in temperature - polymers have the largest values






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






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






39. 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.






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






41. Ability to transmit a clear image - The image is clear.






42. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW






43. Liquid polymer at room T - sandwiched between two sheets of glass - coated with transparent - electrically conductive film. - Character forming letters/ numbers etched on the face - Voltage applied disrupts the orientation of the rod- shaped molecule






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






45. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)






46. 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






47. heat flux = -(thermal conductivity)(temperature gradient) - Defines heat transfer by CONDUCTION

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183


48. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.






49. Wet: isotropic - under cut Dry: ansiotropic - directional






50. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.