课程名称︰普通物理学甲下 课程性质︰共同必修 课程教师︰王建万 开课学院： 开课系所︰生工系 考试日期（年月日）︰2008/4/21 考试时限（分钟）：PM3:30~5:20 (110分钟) 是否需发放奖励金：是 （如未明确表示，则不予发放） 试题 : 08S Mid Term Exam 1. A 6.00g block with a charge of +10.00×10^(-6)C is placed in an electric field E=(4000i-500j) N/C. What are the (a) magnitude and (b) direction (relative to the positive direction of the x axis) of the electrostatic force on the block? If the block is released from rest at the origin at time t=0,what are its (c) x and (d) y coordinates at t=3.00s? (9%) 2. Two isolated, concentric, conducting spherical shells have radii R1=0.600m and R2=1.20m, uniform charges q1=+2.00μC and q2=+1.20μC, and negligible thicknesses.What is the magnitude of the electric field E at radial distance (a) r=4.00m, (b) r=0.800m, and (c) r=0.400m? With V=0 at infinity, what is V at (d) r=4.00m, (e) r=1.20m, (f) r=0.800m, (g) r=0.600m, (h) r=0.300m, and (i)r=0? [1/(4πεo) = 8.99x10^9 N.m^2/C^2] (16%) 3. An electron follows a heilcal path in a uniform magnetic field given by B = (20i-40j-50k)mT. At time t = 0, the electron's velocity is given by v = (30i+20j-50k)m/s. (a) What is the angel ψ between v and B? The electron's velocity changes with time. Do (b) its speed and(c)the angel ψ change with time? (d) What is the radius of the helocal path? (9%) [electron mass m=9.11x10^-31kg, electron charge q=-e=-1.60x10^-19C] 4. In Fig.1, a solid sphere of radius a=3.00cm is concentric with a spherical conducting shell of inner radius b=2.00a and outer radius of c=2.40a. The sphere has a net uniform charge q1=+6.00fC; the shell has a net charge q2=-q1. What is the magnitude of the electric field at radial distances (a) r=0, (b)r=a/2.50, (c) r=a, (d) r=1.40a, (e) r=2.20a, and (f) r=4.00a? What is the net charge on the (g) inner and (h) outer surface of the shell? (16%) 5. In Fig.2, R1 =8.00Ω, R2 =16.0Ω, R3=6.00Ω, and the ideal battery's emf is ξ=24.0 V.For what value of R4 will the rate at which the battery transfers energy to the resistors equal (a)60.0W, (b) the maximum possible rate Pmax, and (c) the minimum possible rate Pmin? What are (d)Pmax and (e)Pmin? (10%) 6. Fig.3 shows a parallel-plate capacitor of plate area A and a separation d. A potential difference Vo is applied between the plates.The battery is then disconnected, and a dielectric slab of thickness b and dielectric constant k is placed between the plates as shown. Assume A = 120cm^2, d = 1.40cm, Vo = 80.0V, b = 0.720cm, and k = 2.80. (a) What is the capacitance Co before the dielectric slab is inserted? (b) What free charge appears on the plates? (c) What is the electric field Eo in the gaps between the plates and the dielectric slab? (d) What is the electric field E1 in the dielectric slab? (e) What is the potential difference V between the paltes after the slab has been indroduced? (f) What is the capacitance with the slab in place between the plates of the capacitor? (12%) 7. Fig.4 is a section of a contucting rod of radius R1 = 1.60mm and length L =12.00m inside a thin-walled coaxial conducting cylindrical shell of radius R2 = 8.00R1 and the same length L. The net charge on the rod is Q1=+4.00x10^-12C; that on the shell is Q2=-2.40Q1.What are the(a) magnitude E and (b) direction (radially inward or outward) of the electric field at radial distance r = 2.00R2? What are (c) E and (d) direction at r = 4.00R1? What is the charge on the(e) interior and (f) exterior surface of the shell? (12%) 8. In Fig.5, a potential difference V =120V is applied across a capacitor arrangement with capacitances C1 =10.0μF, C2 =7.00μF, and C3 =4.00μF. What are (a) charge q3, (b) potential difference V3, and (c) stored energy U3 for capacitor 3, (d) q1, (e) V1, and (f) U1 for capacitor 1, and (g) q2, (h) V2, and (i) U2 for capaciotr 2? (16%) 出处: (第8版) 1.出处 p.602 习题22-53 2.出处 p.652 习题24-66 3.出处 p.759 习题28-30 4.出处 p.625 习题23-51 (Fig.1) 5.出处 p.730 习题27-48 (Fig.2) 6.出处 p.674 Sample Problem 25-7 (Fig.3) 7.出处 p.623 习题23-27 (Fig.4) 8.出处 p.679 习题25-36 (Fig.5) --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 140.112.242.3