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






2. 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






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






4. 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






5. 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.






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






7. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture






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






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






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






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






12. Second phase particles with n > glass.






13. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))






14. Undergo extensive plastic deformation prior to failure.






15. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.






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






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






18. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.






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






20. Cracks propagate along grain boundaries.






21. Elastic means reversible! This is not a permanent deformation.






22. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)






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






24. Undergo little or no plastic deformation.






25. 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.






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






27. 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


28. 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.






29. Width of smallest feature obtainable on Si surface






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






31. 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)






32. 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






33. 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






34. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress






35. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.






36. 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.






37. Reflectiviy is between 0.90 and 0.95 - Metal surfaces appear shiny - Most of absorbed light is reflected at the same wavelength (NO REFRACTION) - Small fraction of light may be absorbed - Color of reflected light depends on wavelength distribution of






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






39. Materials change size when temperature is changed






40. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.






41. Light Amplification by Stimulated Emission of Radiation






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






43. 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






44. Created by current through a coil N= total number of turns L= length of turns (m) I= current (ampere) H= applied magnetic field (ampere-turns/m) Bo= magnetic flux density in a vacuum (tesla)






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






46. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.






47. - 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






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






49. If a material has ________ - then the field generated by those moments must be added to the induced field.






50. High toughness; material resists crack propagation.