課程名稱︰材料科學導論
課程性質︰ 系定必修/外系選修
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）︰2009/06/16
考試時限（分鐘）：80 mins (開講義＆課本)
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
[1] Briefly describe (a) the origins of the magnetic moment of an atom.
(b) the differences among diamagnetism, paramagnetism, ferromagnetism,
antiferromagnetism, and ferrimagnetism.
(15%)
[2] Why the magnetic moment of an atom in the magnetic material will orient to
the applied magnetic field direction if the magnetic field is large enough?
(10%)
[3] Illustrate the boundry in T-H-J (temperature-magnetic field-current density
) space separating superconducting states and normal states.
(10%)
[4] Schematically sketch on a single plot the M-versus-H behavior for a
ferromagnetic material (a) at 0 K, (b) at a temperature just below its
Curie temperature, and (c) at a temperature just above its Curie
temperature. Brief;y explain why these curves have different shapes.
(15%)
[5] Explain why the resistivity of metal is increased with temperature but the
resistivity of intrinsic semiconductor is decreases with increasing
temperature.
(10%)
[6] How does the electron structure of an isolated atom differ from that of a
solid material?
(10%)
[7] Some hypothetical metal is known to have an electrical resistivity of
4x10^-8(Ω-m). Through a specimen of this metal that is 25mm thick is
passed a current of 30A; when a magnetic field of 0.75 tesla is
simultaneously imposed in a direction perpendicular to that of the current,
a Hall voltage of -1.26x10^-7V is measured. Compute (a)the electron
mobility for this metal, and (b)the number of free electrons per cubic
meter.
(10%)
[8] Zinc telluride has a band gap of 2.26eV. Over what range of wavelengths of
visible light is it transparent? (The wavelengths of visible light are
between 0.4μm and 0.7μm. The Plank's constant h=4.13x10^-15eV-s)
(10%)
[9] Briefly explain what determines the characteristic color of (1)a metal and
(2)a transparent nonmetal.
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.112.4.234
※ 編輯: gswnec 來自: 140.112.4.234 (06/16 17:04)