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Test your basic knowledge |
Engineering Materials
Start Test
Study First
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. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Heat Capacity
Magnetic Storage Media Types
Diamagnetic Materials
There is no perfect material?
2. Cracks propagate along grain boundaries.
Film Deposition
Paramagnetic Materials
Intergranular Fracture
Dependence of Heat Capacity on Temperature
3. Width of smallest feature obtainable on Si surface
What do magnetic moments arise from?
Linewidth
Conduction & Electron Transport
Reflectance of Non-Metals
4. 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.
Coefficient of Thermal Expansion
Thermal Conductivity
Brittle Ceramics
Liquid Crystal Displays (LCD's)
5. Second phase particles with n > glass.
Brittle Ceramics
Why fracture surfaces have faceted texture
Intrinsic Semiconductors
Opacifiers
6. Ohms Law: voltage drop = current * resistance
Meissner Effect
Electrical Conduction
Slip Bands
The three modes of crack surface displacement
7. Increase temperature - increase in interatomic separation - thermal expansion
Why fracture surfaces have faceted texture
Thermal Expansion: Asymmetric curve
Domains in Ferromagnetic & Ferrimagnetic Materials
There is no perfect material?
8. Ability to transmit a clear image - The image is clear.
Plastic Deformation (Metals)
Transparent
Why do ceramics have larger bonding energy?
Lithography
9. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Opacity
Engineering Fracture Performance
Hardness
Insulators
10. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Incoherent
Charpy or Izod test
There is no perfect material?
Ductile Materials
11. Resistance to plastic deformation of cracking in compression - and better wear properties.
Large Hardness
What do magnetic moments arise from?
Thermal Shock Resistance
Coherent
12. 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
True Stress
Extrinsic Semiconductors
Reflection of Light for Metals
Bending tests
13. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Work Hardening
Superconductivity
Generation of a Magnetic Field - Within a Solid Material
Shear and Tensile Stress
14. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
LASER
Transgranular Fracture
Diamagnetic Materials
Extrinsic Semiconductors
15. Wet: isotropic - under cut Dry: ansiotropic - directional
Extrinsic Semiconductors
Etching
Domains in Ferromagnetic & Ferrimagnetic Materials
Diamagnetic Materials
16. The size of the material changes with a change in temperature - polymers have the largest values
M is known as what?
Liquid Crystal Displays (LCD's)
The Transistor
Coefficient of Thermal Expansion
17. - 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
Stress Intensity values
HB (Brinell Hardness)
Thermal Stresses
Liquid Crystal Displays (LCD's)
18. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Dependence of Heat Capacity on Temperature
Thermal Expansion: Symmetric curve
Thermal Stresses
Hysteresis and Permanent Magnetization
19. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Intergranular Fracture
Internal magnetic moments
Soft Magnetic Materials
Generation of a Magnetic Field - Vacuum
20. Light Amplification by Stimulated Emission of Radiation
Where does DBTT occur?
Luminescence
Paramagnetic Materials
LASER
21. If a material has ________ - then the field generated by those moments must be added to the induced field.
Linewidth
Stress Intensity Factor
Internal magnetic moments
Dependence of Heat Capacity on Temperature
22. Without passing a current a continually varying magnetic field will cause a current to flow
Thermal Shock Resistance
What do magnetic moments arise from?
Response to a Magnetic Field
The Transistor
23. - 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
Luminescence
Pure Semiconductors: Conductivity vs. T
The Transistor
Thermal Stresses
24. Materials change size when temperature is changed
Why materials fail in service
Thermal expansion
Metallization
Charpy or Izod test
25. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Energy States: Insulators and Semiconductors
Why fracture surfaces have faceted texture
Domains in Ferromagnetic & Ferrimagnetic Materials
Why materials fail in service
26. These materials are "attracted" to magnetic fields.
Incoherent
Yield and Reliability
Paramagnetic Materials
Shear and Tensile Stress
27. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Metals: Resistivity vs. T - Impurities
Heat Capacity
Opacifiers
Refraction
28. 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.
Conduction & Electron Transport
Hard Magnetic Materials
Reflectance of Non-Metals
Valence band
29. 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.
Coefficient of Thermal Expansion
Ductile Fracture
M is known as what?
Thermal Conductivity
30. 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.
Heat Capacity
Energy States: Insulators and Semiconductors
Luminescence examples
Liquid Crystal Displays (LCD's)
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)
Rockwell
Reflection of Light for Metals
Incoherent
Engineering Fracture Performance
32. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Large Hardness
Color
Valence band
Energy States: Insulators and Semiconductors
33. Typical loading conditions are _____ enough to break all inter-atomic bonds
Yield and Reliability
Internal magnetic moments
Not severe
Two kinds of Reflection
34. There is always some statistical distribution of flaws or defects.
Intergranular Fracture
There is no perfect material?
Generation of a Magnetic Field - Within a Solid Material
Thermal Shock Resistance
35. The ability of a material to be rapidly cooled and not fracture
Critical Properties of Superconductive Materials
Thermal Shock Resistance
What do magnetic moments arise from?
Why materials fail in service
36. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Brittle Materials
Metallization
Liquid Crystal Displays (LCD's)
Hard Magnetic Materials
37. Undergo little or no plastic deformation.
Rockwell
Brittle Materials
Reflection of Light for Metals
Impact - Toughness
38. Is analogous to toughness.
Impact energy
Magnetic Storage
Luminescence examples
Soft Magnetic Materials
39. 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
Critical Properties of Superconductive Materials
Hard Magnetic Materials
The Transistor
Lithography
40. 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
Incident Light
What do magnetic moments arise from?
Specific Heat
Oxidation
41. High toughness; material resists crack propagation.
Work Hardening
Critical Properties of Superconductive Materials
Engineering Fracture Performance
High impact energy
42. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Magnetic Storage
IC Devices: P-N Rectifying Junction
Heat Capacity from an Atomic Prospective
Insulators
43. Elastic means reversible! This is not a permanent deformation.
Elastic Deformation
Why materials fail in service
Two kinds of Reflection
Opaque
44. A high index of refraction (n value) allows for multiple internal reactions.
Sparkle of Diamonds
High impact energy
Electrical Conduction
Etching
45. Sigma=ln(li/lo)
Refraction
Translucent
True Strain
How an LCD works
46. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Thermal Conductivity
Linewidth
Metals: Resistivity vs. T - Impurities
Brittle Fracture
47. 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."
Thermal Stresses
Charpy or Izod test
Heat Capacity
Opaque
48. 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.
Heat Capacity
Refraction
Incident Light
Thermal Shock Resistance
49. 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
Magnetic Storage
Heat Capacity
Hardness
Thermal Stresses
50. 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
Transparent
Iron-Silicon Alloy in Transformer Cores
High impact energy
Hysteresis and Permanent Magnetization