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






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






3. 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.






4. Emitted light is in phase






5. 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.






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






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






8. Width of smallest feature obtainable on Si surface






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






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






11. 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






12. 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.






13. Growth of an oxide layer by the reaction of oxygen with the substrate - Provides dopant masking and device isolation - IC technology uses 1. Thermal grown oxidation (dry) 2. Wet Oxidation 3. Selective Oxidation






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






15. 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






16. 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)






17. 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.






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






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






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






21. Sigma=ln(li/lo)






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






23. 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.






24. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.






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






26. Is analogous to toughness.






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






28. - 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






29. 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






30. Different orientation of cleavage planes in grains.






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






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






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






34. 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






35. Ohms Law: voltage drop = current * resistance






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






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






38. Occur when lots of dislocations move.






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






40. 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






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






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






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






44. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe






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






46. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel






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






48. 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.






49. 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.






50. 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







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