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






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






3. A high index of refraction (n value) allows for multiple internal reactions.






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






5. Emitted light is in phase






6. 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.






7. Ohms Law: voltage drop = current * resistance






8. Diffuse image






9. Sigma=ln(li/lo)






10. - 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






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






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






13. Different orientation of cleavage planes in grains.






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






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






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






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






18. 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.






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






20. Cracks propagate along grain boundaries.






21. 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."






22. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals






23. 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


24. 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






25. Occur when lots of dislocations move.






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






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






28. 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






29. Because of ionic & covalent-type bonding.






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






31. 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.






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






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






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






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






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






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






38. 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.






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






40. 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.






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






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






43. 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.






44. 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






45. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.

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


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






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






48. The Magnetization of the material - and is essentially the dipole moment per unit volume. It is proportional to the applied field. Xm is the magnetic susceptibility.






49. 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






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