課程名稱︰材料科學導論 課程性質︰必修 課程教師︰郭博成 開課學院：工學院 開課系所︰材料系 考試日期（年月日）︰2008/6/17 考試時限（分鐘）：150分鐘 是否需發放獎勵金：是 （如未明確表示，則不予發放） 試題 : 1.Why the magnetic moment of an atom in the magnetic material will oreien to the applied magnetic field direction if the magnetic filed is large enough? (10%) 2.Describe the change of domain configurations during magnetization for a magnetic material.(10%) 3.Cite the major similarities and differences between ferromagnetic and ferrimagnetic materials.(15%) 4.Cite the differences between type I and type II superconductors.(10%) 5.Explain why the resistivity of metal is increased woth temperature but the resistivity of intrinsic semiconductor is decreased with increasing temperature.(10%) 6.How does the electron structure of an isolated atom differ form that of a solid material?(10%) 7.Some hypothetical metal is known to have an electrical resistivity of 4*10^-8 (Ω-m). Through a specimen of this mental that is 25mm thick is passed a current of 30 A ; when a magnetic field of 0.75 tesla is simultaneously imposed in a direction perpendicular to to that of the current, Hall voltage of -1.26*10^-7 V is measured. Compute (a) the electron mobility for this metal, and (b) the number of free electrons per cubic meter. (10%) 8.Consider a parallel-plate capacitor having an area of 2500 mm^2 and aplate separation of 2 mm, and with material of dielectric constant 4.0 positioned between the plates. (a)What is capacitance of this capacitor? (b)Compute the electric field that must applied for a charge of 8.0*10^-9 C to be stored on each plate (10%) 9.Briefly explain determines the characteristic color of (1) a metal and (2) a transparent nonmetal. (15%) --

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