
10-11电路分析补充习题答案.doc
9页S闭合时,有消耗功率提供功率提供功率提供功率提供功率提供功率1.1、解应用欧姆定律,得200-(-50) 为= ——=10 mAz 200-(-100) a A 11= =6 mA40 + 10 ~ 20 + 5崎=10/|+(-100)=6x 10-100=-40V Vb=572+(-50)=5x \ 0-50=0Uab= Va -Vb=-40V-12-121・2、S打开时,有昨= x20+12=.8V3 + 1 + 200-12 *= x20+12=0.57 V1 + 201- 3、(a)/ = -l mA (b) i(t) = 3e21 A (c) (/)= lOOcos/V (d) U= 1 VP = 0.1 W1- 4、解根据功率计算公式及题给条件,得(a) J4b=6V,P=6x2= 12W(b) Sb=-8V, P=lx(-8)=-8W(c) Lb=・10V, P=・(・8)X(.10)=.80W(d) Uab=-8V,P=-(-2)X(.8)=-16W(e) t/ab=-(-6)=6V P=-(-1) X (-6)=-6W(f) Uab=-16V, P=(-2)X 16=・32W1- 5、KVL: 14 = 5/1+13x2 + 2/l =2AKCL:介=1AKVL : U/g = (2 x 1 + 2) V = 4 VR = 4Q2.1、(白)R = 35Q,(幻& = 1。
2- 2. (a)t/c=15V,怡=5 (b) f/oc=100V;昭=52- 3 > (a)I = 0.5A; (b) I = 8A2- 4解采用外加电源法求Rab题2-4图(a)应用 KCL、KVL,得u, 汁 2"i=——2 ||1求出 7?ab= —=-Hil(b)由欧姆定律及KCL,得 i2=-— i]=,+2曲『Bi•您2 ~ 2应用 KVL,得 姻=2"+4,3=2(3,-性J+4(,.性■)2可求出喝7 = ?=2.5Q3- 1解 以O点为参考点,选独立回路时,回避无伴电流源所在的网孔,选另外两个网孔为独立回路, 以顺时针方向作为回路绕行方向,可得下列支路电流方程-知+,2+,6=0-五+,3+,4=0-,4+,5~,6=0-玲3+即4+四5=火3--汽4,4+汽6,6=- 〃S6代入己知条件得-1+,2+,6= 、・ &+,3+14=0-Z4+^5-,6=0 〉-4/3+8/4+8/5=20解方程得-10/2- 8,4+2姑=-40 >/2=2.2143 A, ,3=0.2857A, /4= 1.9286AR】题3-3图4=0.7143 A, i6=- 1.2143 A3.2解3个独立回路如图所示,其回路电流方程为 //1=/s4=5/?2力1+(R2+R5+R3)//2-&3//3=化2+%3-%5 7,3=0.25(72[/2=-犬2(//1+板) 代入己知条件,整理得。
5 6.25//1+8.25//2 =23 -7/3=-1-25 (/n+fe),解方程得 7/]=5A, 112=-1A //3=-5A则 /3=//2-//3=-l -(-5)=4A3- 3 I = 5A3- 4解 以0点为参考结点,结点电压方程为1 1 1 )如一5 ""6Un2=61 1 1^N2+( — +— )Un3=-64 2 4整理得4#ni-Un2=18 U"6 -贝 2+3Un3=-24<解之得 Uni=6V, l/N2=6V, Un3=-6V则 U=Uni-Un3=6-(-6)=12V I——h —6- — =3A3- 5解以0点为参考结点,其结点电压方程为 (2+2+2) Un】-2Un2=-2x10 因2=2/2 .,2=2Uni .求得Uni=10V, Un2=40V 则受控源的电流及功率为/=2(Uni-〃n2)-1,n2=-100AP2I =2/2/=2x2/7Nj/=2x2x 10x(-100)= -4000W4- 1解2A电流源单独作用时,有1x(2 —广)=2/ + 3(/ + 2/)u - 3(,+ 2/)求得zz = -A # = 3x3x1 =6 61.5V4V电压源单独作用时,有4 = (1 + 2>〃 + 3(尸+2广)、“〃 =3(/ + 2广) -求得•" 1 ai =-A3〃" = 3x3xL = 3V3由叠力口定理得 i = / + r = ]+【= 0.5A “ = / + / = 1.5+ 3 = 4.5V6 3受控源的功率为 p = -2iu = -2 x 0.5 x 4.5 = -4.5W4- 2解由条件(1)可知网络N是含源的,设U = KiUsi+K.U +U式中U为N内部独立源产生的U的分量。
将题给条件代入上式,得1 = / 32 = K\+U‘ —i = Y+tr求出 U = 1V, K|=1, K2 =-2则Usi和〃S2为任意值时,电压U的计算公式为U =Usi— 2〃S2 +1 4.3解R所在支路的电流,已知,根据替代定理可用一个电流源is=i替代之,设u = Kis +=Ki + u式中"为N内部独立源所产生的〃的分量将己知条件代入上式,得20=Kxl + / 30=Kx2 + / ■解得 K = 10, / = 10V即有 w = 10/ + 10当i = 3A时,由上式可得 m = 10x3 + 10 = 40V4- 4解(a)设1-1’端口电压为U ,电流为/,应用KCL及KVL得〃 = 20(/ + l) + 0.6x3/ + 10整理得 U =30 + 21.8/即得t4=30V,《q=21.8Q, Zsc =^- = 1.376A oc cq sc 21.8(b)设1-1端口电压为U ,电流为/,应用KCL及KVL得U-3/-5 U-3I ,,3 6整理得"=5.333 + 5/即得= 5.333V, 7?cq =5Q, /sc =^2 = 1.067A vv so 54- 5解将3V电压源拿掉,形成含源一端口,其等效戴维宁参数求解如下:应用KCL、KVL得4(1-/) = -2/+ 6/求出/ = 0.5A 开路电压为U, = 6/ = 6 X 0.5 = 3V用外加电源法可求出&曙=6。
则/皿+3=22 = ]a心 63V电压源吸收的功率为 p = -3/,=-3xl = -3W (实际发出功率3W)4- 6解将R拿掉,形成含源一端口,其开路电压为Uab2 + 20 + 4x5 = 42V等效戴维宁电阻为Rs =6 + 4 = 100U2 422则当R = % =10时,可获得最大功率,其值为已亦== =44.1Weq max 4Rcq 4x105- 1 /、(()+) = 24V, "(0+) = 2A, 〃(0『)= -8V5- 2 雄)= 0.72cWV t>05- 3 气(0 = -24节”乂 w心=3J5- 4 z(Z) = e16/ A5- 5 w(r) = (-12 + 3.6e-5/) V5-6 "(,) = (4+ 0.8) VS 75对展)=(+ 疽)A o o5- 8 u(t) = [9(0-15(r-ls) 一 3(1- e-/)(0 + 5(1- e",+,s)(/-ls)]V6- 1 U=70.7V, /|=1.414A, /2=2.828A, G=3.535A;心=10,/ =100% =10 % =-80△伊i =一90,△代=0,△仞3 =906- 2 (a) w=10cos(69r-10)V (b)w=10 V2 cos(C-127)V(c) z=20.8cos(d> r-89.4)A (d)z=30 V2 cos(691+180)A6- 3 R=5.09Q,L=13.7mH6- 4 (a)U = 30V, / = 3A (b)U = 60VJ = 2.33A (c)U = 50V, / = 1A6- 5 R = Xl,Xc=・Xl6-6 CD = 500rad/s, Z = (160 - j30)Q; R = 160Q, C = 66.6pF;0)= 1 OOOrad/s, Z = 100Q; /? = 100。
co = 2000rad/s,Z = (40 + jl 20)Q; R = 40Q, L = 0.06H6-7 "|2=10 应 cos(6yr+116.6)V6-8 U()C =40V2Z135V,Z/h =22.36453.436-9 Qi=60Var, Q2= - 40Var, S|=100VA, S2=50VA,P= 110W, e=20Var,S=l 11.8VA, 2=0.9846-10 (1) Z=48.1A,X=0.756, (2) C=2O1|1F,/=40.4A6-11 uar = 538.67cos(欲)= 538.67cos(仞 一 120)V, uca = 538.67cos(q/ +120)V6- 12 PY=8.7kW, =26kW7- 1(1) R = 0.1 = ImH,C = 10pF,Q = 100 (2)uc — lOV^cos(仞一90)V3—2一—43R 2RI7R I3K5\3(=3)s2Q1(b) Z NK + s(>+.rl2M) s(rIM) SB IM) SP+一,sC7—2 UCH530.3V UH545.2V8*Tl.57>pn73.95w8—2(l)*80.0 一 slr58.74mA” (2)R3.42W一。
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