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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. 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.
Brittle Ceramics
Fatigue
Insulators
Meissner Effect
2. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Griffith Crack Model
To improve fatigue life
Extrinsic Semiconductors
Incoherent
3. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Griffith Crack Model
Thermal Expansion: Symmetric curve
Energy States: Insulators and Semiconductors
Modulus of Rupture (MOR)
4. Is analogous to toughness.
Transparent
Linewidth
Thermal expansion
Impact energy
5. 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
Lithography
Hysteresis and Permanent Magnetization
To improve fatigue life
Metals: Resistivity vs. T - Impurities
6. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Valence band
Pure Semiconductors: Conductivity vs. T
Impact energy
Stress Intensity Factor
7. Sigma=ln(li/lo)
Not severe
Holloman Equation
True Strain
The Transistor
8. Resistance to plastic deformation of cracking in compression - and better wear properties.
Metallization
Stress Intensity values
Large Hardness
Brittle Materials
9. Transformer cores require soft magnetic materials - which are easily magnetized and de-magnetized - and have high electrical resistivity - Energy losses in transformers could be minimized if their cores were fabricated such that the easy magnetizatio
The three modes of crack surface displacement
Thermal Shock Resistance
Influence of Temperature on Magnetic Behavior
Iron-Silicon Alloy in Transformer Cores
10. Occur when lots of dislocations move.
Color
Slip Bands
Linewidth
Influence of Temperature on Magnetic Behavior
11. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
True Strain
Why materials fail in service
Ductile Fracture
Ductile-to-Brittle Transition
12. Emitted light is in phase
Modulus of Rupture (MOR)
Critical Properties of Superconductive Materials
Coherent
Refraction
13. 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
Modulus of Rupture (MOR)
Electromigration
Luminescence examples
14. Metals are good conductors since their _______is only partially filled.
Valence band
HB (Brinell Hardness)
Why do ceramics have larger bonding energy?
Opacity
15. 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
The Transistor
Luminescence
Fourier's Law
Hard Magnetic Materials
16. Stress concentration at a crack tips
Griffith Crack Model
Generation of a Magnetic Field - Vacuum
Engineering Fracture Performance
Two kinds of Reflection
17. 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.
Transparent
Heat Capacity
IC Devices: P-N Rectifying Junction
Thermal expansion
18. Elastic means reversible! This is not a permanent deformation.
Elastic Deformation
Rockwell
Magnetic Storage
Luminescence examples
19. 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
Ductile-to-Brittle Transition
Stress Intensity Factor
Griffith Crack Model
Metals: Resistivity vs. T - Impurities
20. There is always some statistical distribution of flaws or defects.
Modulus of Rupture (MOR)
There is no perfect material?
Pure Semiconductors: Conductivity vs. T
Film Deposition
21. Cracks propagate along grain boundaries.
Meissner Effect
Transgranular Fracture
Extrinsic Semiconductors
Intergranular Fracture
22. The ability of a material to be rapidly cooled and not fracture
How to gage the extent of plastic deformation
What do magnetic moments arise from?
Thermal Shock Resistance
Fourier's Law
23. 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)
Generation of a Magnetic Field - Vacuum
Oxidation
Plastic Deformation (Metals)
Why do ceramics have larger bonding energy?
24. Second phase particles with n > glass.
Ductile Materials
Why fracture surfaces have faceted texture
Opacifiers
Griffith Crack Model
25. - 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
Why do ceramics have larger bonding energy?
Refraction
Electromigration
Stress Intensity values
26. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Metallization
Intrinsic Semiconductors
Incident Light
Soft Magnetic Materials
27. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Diamagnetic Materials
Engineering Fracture Performance
Domains in Ferromagnetic & Ferrimagnetic Materials
Metals: Resistivity vs. T - Impurities
28. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Ductile Materials
Reflectance of Non-Metals
True Stress
Response to a Magnetic Field
29. Without passing a current a continually varying magnetic field will cause a current to flow
Work Hardening
Response to a Magnetic Field
Holloman Equation
True Stress
30. 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."
Insulators
Charpy or Izod test
Incoherent
Magnetic Storage Media Types
31. 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.
Reflectance of Non-Metals
Critical Properties of Superconductive Materials
Incident Light
Impact - Toughness
32. 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.
M is known as what?
True Strain
Specific Heat
Translucent
33. Width of smallest feature obtainable on Si surface
Linewidth
Shear and Tensile Stress
True Stress
How an LCD works
34. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Superconductivity
Force Decomposition
Conduction & Electron Transport
Thermal Conductivity
35. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Heat Capacity from an Atomic Prospective
Internal magnetic moments
LASER
HB (Brinell Hardness)
36. Wet: isotropic - under cut Dry: ansiotropic - directional
Opacity
Brittle Fracture
Large Hardness
Etching
37. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Specific Heat
What do magnetic moments arise from?
Not severe
Metallization
38. These materials are relatively unaffected by magnetic fields.
Generation of a Magnetic Field - Within a Solid Material
Oxidation
Diamagnetic Materials
Energy States: Insulators and Semiconductors
39. Because of ionic & covalent-type bonding.
Soft Magnetic Materials
Why do ceramics have larger bonding energy?
Luminescence
Refraction
40. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Why materials fail in service
Dependence of Heat Capacity on Temperature
Modulus of Rupture (MOR)
Lithography
41. These materials are "attracted" to magnetic fields.
Transparent
Paramagnetic Materials
To improve fatigue life
Ductile-to-Brittle Transition
42. Becomes harder (more strain) to stretch (elongate)
Work Hardening
Conduction & Electron Transport
Hardness
Valence band
43. Undergo extensive plastic deformation prior to failure.
Metals: Resistivity vs. T - Impurities
Ductile Materials
Oxidation
Two ways to measure heat capacity
44. Undergo little or no plastic deformation.
Meissner Effect
Heat Capacity
Brittle Materials
Sparkle of Diamonds
45. Light Amplification by Stimulated Emission of Radiation
Impact energy
Thermal expansion
LASER
Electrical Conduction
46. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
True Strain
Film Deposition
Sparkle of Diamonds
Fatigue
47. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
To improve fatigue life
Linewidth
Engineering Fracture Performance
Internal magnetic moments
48. Increase temperature - increase in interatomic separation - thermal expansion
Luminescence examples
High impact energy
Response to a Magnetic Field
Thermal Expansion: Asymmetric curve
49. Specific heat = energy input/(mass*temperature change)
Specific Heat
Charpy or Izod test
Work Hardening
Response to a Magnetic Field
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
High impact energy
Magnetic Storage
Two ways to measure heat capacity
Hard Magnetic Materials