课程名称︰普通物理学 课程性质︰物理系必修 课程教师︰张宝棣 开课学院：理学院 开课系所︰物理系 考试日期（年月日）︰2013/06/20 考试时限（分钟）：200 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 1. Please explain the following questions. a.What is left-handed circularly polarized light? What is Fermat's priciple to explain the reflection and refraction of light?(5%) b.What is Ferromagnetism? Explain why the magnetization of paramagnetic materials is temperature dependent.(5%) c.Write down the Maxwell's equation. What is transformer?(5%) 2.In Fig. 1, R=15.0 Omega, C=4.70 uF, and L=25.0mH. The generator provides an emf with rms voltage 75.0V and frequency 550Hz. (a)What is rms current? What is the rms voltage across (b)R, (c)C, (d)L, (e)C and L together, and (f)R,C,and L together? (10%) 3.Given that the driving voltage of the RLC circuit shown in Fig. 2 is V=V0cos(wt), calculate the current in the three elements. Is there a resonance frequency?(Hint: One can use a phasor to find the relation between I and V in each element or write down the circuit equations, and substitute the trial solution I=I0cos(wt+fi). (15%) 4.A plane electromagnetic wave varies sinusoidally at 90.0 MHz as it travels along +x direction. The peak value of the electric field is 1.00 mV/m, and it is directed along the +-y direction.(a) Find the wavelength, the period, and the maximum value of the magnetic field.(6%) (b) Find the average power per unit area that this wave carries through space.(3%) (c)Find the average energy density in the radiation(in joules per cubic meter. 3%) (d) What radiation pressure would this eave exert upon a perfectly reflecting surface at normal incidence?(3%) 5.We want to rotate the direction of polarization of a beam of polarized light through 90 degress by sending the beam through one or more polarizing sheets. (a) What's the minimum number of sheets required?(5%) (b) What is the minimum number of sheets required if the transmitted intensity is to be more than 60% of the original intensity? (5%) 6.A thin layer of CaF2(n=1.41) is deposited onto glass, with n=1.52. The thin layer is viewed in reflected light as 45 degrees using a white light source (Fig.3). For what layer thickness will light of 640nm show totally constructive interference? Are there possible thickness for which light of 480 nm interference totally constructively as well? Please explain?(15%) 7.Three slits, each seperated from its neighbor by 0.06 nm, are illuminated by a coherent light source of wavelength 559nm. The slits are extremely narrow. A screen is located 2.5m from the slits. The intensity on the centerline is 0.05W/m^2. Consider a location 1.72 cm from the centerline. (a) Draw the phasors, according to the phasor model for the addition od harmonic waves, appropriate for this location. (b)From the phasor diagram, calculate the intensity of light of this location.(10%) 8.(a)How many bright fringes appear between th dirst diffraction-envelope minimum to either side of the central maximum in double slits pattern if 入=550nm, d=0.15mm and a=30.0um? (b) What is the ratio of the third bright fringe to teh intensity fo the central fringe? (10%) 图:http://i.imgur.com/NBxrafh.jpg -- 标题 Re: [新闻] 两俄国客在波兰逃票并将一头棕熊打成重伤 --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 118.168.65.68