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. High toughness; material resists crack propagation.






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






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






4. 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.






5. 1. Stress-strain behavior is not usually determined via tensile tests 2. Material fails before it yields 3. Bend/flexure tests are often used instead.






6. 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


7. 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






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






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






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






11. - 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






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






13. The magnetic hysteresis phenomenon: Stage 1: Initial (unmagnetized state) Stage 2: Apply H - align domains Stage 3: Remove H - alignment remains => Permanent magnet Stage 4: Coercivity - Hc negative H needed to demagnitize Stage 5: Apply -H - align d






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






15. 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






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






17. 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






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






19. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R






20. Resistance to plastic deformation of cracking in compression - and better wear properties.






21. Emitted light is in phase






22. 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.






23. 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






24. These materials are relatively unaffected by magnetic fields.






25. 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






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






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






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






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






30. Undergo extensive plastic deformation prior to failure.






31. Materials change size when temperature is changed






32. 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.






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






34. Occur when lots of dislocations move.






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






36. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.






37. Stress concentration at a crack tips






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






39. - The emission of light from a substance due to the absorption of energy. (Could be radiation - mechanical - or chemical energy. Could also be energetic particles.) - Traps and activator levels are produced by impurity additions to the material - Whe






40. Becomes harder (more strain) to stretch (elongate)






41. A measure of the ease with which a B field can be induced inside a material.






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






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






44. 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






45. Not ALL the light is refracted - SOME is reflected. Materials with a high index of refraction also have high reflectance - High R is bad for lens applications - since this leads to undesirable light losses or interference.






46. Cracks propagate along grain boundaries.






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






48. Ohms Law: voltage drop = current * resistance






49. 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






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