精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰熱物理學 課程性質︰必修 課程教師︰王名儒 開課學院:理學院 開課系所︰物理系 考試日期(年月日)︰2008/1/15 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. The specific Gibbs free energy for a gas is given by g=RTln(P/P0)-AP, where A is a function of T only and P0 is a constant. Find the expressions for the following quantities:(a) the equation of state (5 points);(b) the specific entropy (5 points) (c) the specific Helmholtz free energy (5 points) (d) the constant pressure specific heat capacity Cp (5 points) 2. Please draw the phase diagram (i.e. P-T projections of different phases) of H2O. The solid region, liquid region, vapor region, gaseous region, fusion curve, vaporization curve, sublimation curve, triple point and critical should be labeled (5 points). Derive the Clausius-Clapeyron equation, dP/dT=(s2-s1)/(v2-v1), which describes the first-order phase-transition curves on the phase diagram, where 1 and 2 denote different phases (10 points). Use this equation and the assumption of ideal gas to find the functional form of the vaporization curve (5 points). Show that the obtained result is a good approximation to the saturated vapor pressure at fixed T, where other gas milecules are also presented in the atmosphere (10 points). You need to show the chemical potential of vapor first, μ=g+RTlnx using an ideal gas mixing process where x is the mole-fraction of H2O in the gas state and g is the specific Gibbs free energy for pure H2O vapor without any other mixing components (10 points) 3. Derive the following equation for the incident flux Φ=1/4 nv of an ideal gas, where n is the number density and v is the average speed of the gas, assuming a uniform and isotropic condition (10 points). Show that the equation of state of the photon gas is PV=1/3 U where U is the total energy of state of the photons (10 points) 4. Derive the Bose-Einstein distribution for an isolated system consisting of one ideal Bose gas. The energy level εi and the degeneracy of the energy state, gi are assumed to be known. The total number of particles,N, and the total energy,E, are conserved. You need to use the Largrange multiplier method in order to derive the B.E. distribution at thermal equilibrium. Note that you don't need to find out the two Largrange multipliers in the derivation but you need to argue their physical meanings using a dilute gas limit (20 points) -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.251.247
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