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. 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






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






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






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






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






6. 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






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






8. 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






9. 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.






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






11. 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






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






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






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






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






16. 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.






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






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






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






20. Is analogous to toughness.






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






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






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






24. Undergo extensive plastic deformation prior to failure.






25. 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)






26. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)






27. Stress concentration at a crack tips






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






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






30. 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.






31. 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






32. Emitted light is in phase






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






34. 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.






35. 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






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






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






38. Undergo little or no plastic deformation.






39. 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






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






41. 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.






42. 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






43. 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


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






45. Sigma=ln(li/lo)






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






47. 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.






48. High toughness; material resists crack propagation.






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






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







Sorry!:) No result found.

Can you answer 50 questions in 15 minutes?


Let me suggest you:

Browse all subjects

Browse all tests

Most popular tests



Major Subjects

Tests & Exams


AP
CLEP
DSST
GRE
SAT
GMAT

Browse all subjects

Browse all tests

Most popular tests