【正文】 * * * * * * * * * * story. Here, let me to cast a brick to attract jade, speak about our highway. Highway line section of the road surface transformation project, last year towards the country seized will be seized one of the items. To plete this arduous task, as a project management office director Comrade, keep in mind from the Communist Party membership, recognize and identify the bottom line, strict management, and strict adherence to the quality of the project. He not only set an example, honesty and selfdiscipline, but also requires the management of all the members of the ., do not eat the construction unit one meal, do not accept the construction unit a ceremony. In this way, they didn39。 difficult to myself to move away the heart of stone head. Leave time to spend with her, often reflect my heart, so as to remove your heart of stone. 24, everything does not have to be demanding, e to, everything does not have to care about, over the past。 but the most important is good to cherish their own. 21, life, select the plex, is to choose the pain。 to be alive, you will have trouble. Life is the most afraid of what all want to care about, but also what all grasp is not firm, without scenery, separated populations, such as not to desire, all docked in the fate of the end. Why is too rigid, the natural, to go stay not to live, let go of obsession, revel is 20, if the fate of the broken Hopes of sailing, please don39。t lose your life and the life, respectively is: the former is a we experienced cannot escape in a day finally will last minute, while the latter is our persistent, we want to cherish the memory of those people and things. 14, learn to smile, learn to strong, the world you know so many people, so many people and you are, you cannot change also can39。 no matter how many grievances, how unfortable, and ultimately to heal themselves or their own, others may got you to fort, but never know your heart is how wanjianchuanxin. 12, ma39。 now want anything, for fear that others know, or like to lose the same. 9, the heart move, everything in the world is followed by birth, Rangrang, important thing is often the most difficult to open one39。 life happy and worry, all is you of life attitude, optimistic, good luck。 I am not afraid of the truth to tell the best friend, I39。t always take everything back to things, and don39。 to discipline a ruler, often the control inspection, and consciously in the ideological red line to draw the row Ming Good accumulation is indeed the bottom line, so that the heart has fear, said to have quit, the line has ended. Attached: indifferent to heart, calmly to the table in our life, there are many unpredictable things will happen, some good, some bad things, we cannot control is powerless to stop, but with time, you will find in life sometimes turns out to be not good, some bad things finally turned out to be a good thing, but then we muddy however did not know, this is the life teach us things. 1, life can be plex, can also be simple. Want simple life of precipitation, to have enough time to reflect, to make Bee more perfect. Life is the most important thing is not to win, but the struggle。求各相電流值。 圖 習(xí)題 電路圖 解 由于 22 )( LRUI ??? 當(dāng) rad /s314502 ??? ?? 時(shí)， A10?I ， V220?U 得 22 )314(22020 LR ?? 當(dāng) ra d /s12562020 ??? ?? 時(shí)， 5A?I ， V022?U 得 22 )125 6(0225 LR ?? 解得 ??? LR ，　 。 圖 習(xí)題 電路圖 解 V020 oSS ??? ?Uu ， ???? 12020SIUR 由于 10202000 ??L?， 所以 mH10100 010100 ??? ?L。 圖 習(xí)題 電路圖 解 諧振頻率 s/r a d102 11 360 ?????? ?LC? 品質(zhì)因數(shù) 524 30 ????? R LQ ? 諧振電流 A144S0 ??? RUI 電阻兩端的電壓 V4SR ??UU 電感及 電容 兩端的電壓 V100425SCL ????? QUUU 在 RLC 并聯(lián)諧振電路中，已知 ??10R ， μH250?L ，諧振頻率 Hz1040 ?f 。 圖 習(xí)題 電路圖 解 ??????????????? 1 8 . 43 . 1 6j32j2j14j4 4j4j1Z 05 ooS ???? ???? ?? ZUI 網(wǎng)絡(luò) N 吸收的有功功率 o o s o ????? ?UIP 無(wú)功功率 v a in o ????? ?UIQ 功率因數(shù) o sc o s o ??? ?? （滯后） 視在功率 ??UIS 某一供電站的電源設(shè)備容量是 kVA30 ，它為一組電機(jī)和一組 W40 的白熾燈供電，已知電機(jī)的總功率為 1kW1 ，功率因數(shù)為 ，試問(wèn)：白熾燈可接多少只？電路的功率因數(shù)為多少？ 解 電機(jī)的視在功率： ? ?kV A20 ??S 白熾燈消耗總功率： (k W )102030 ???P 白熾燈可接的燈數(shù)為： 2504010000?(盞 ) ???? 圖 所示電路 中 ，已知正弦電壓為 Hz50V220S ?? fU ， ，其功率 因數(shù) ?? ，額定功率 ?P 。 （ a）電路 (b) 相量模型 圖 習(xí)題 電路圖 解 將時(shí)域模型轉(zhuǎn)化為相量模型如圖（ b） 用有效值相量計(jì)算， V904 oSS ???? ?Uu ， ? ? ????????? ???? 452j1jj2 j)j ) ((221Z A4522452 904 o1 ?????? ???????ZUI S A452jj2 j o1 ??????? ?? II ? ?A45 sin2 ??? ti )j( 1 ?????????? ??? IIU ? ? 08 s i ??? tu W8)45c o s (224)4590c o s ( oo1S ????????? IUP 日光燈可以等效為一個(gè) RL 串聯(lián)電路，已知 W30 日光燈的額定電壓為 V220 。 (a) 電路 (b) 相量模型 圖 習(xí)題 電路圖 解 將時(shí)域模型轉(zhuǎn)化為相量模型如圖 (b) 當(dāng) 電流源 S1i 單獨(dú)工作時(shí)， 利用 分流公式 得 01j1 ????? ??????????I 當(dāng) 電流源 S2i 單獨(dú)工作時(shí)，利用 分流公式 得 2 . 500 . 52 ???????????I o21 ???? ??? ????? ??? III ? ? 5s ??? ti 用疊加原理計(jì)算圖 中的 電壓 ?U 。 圖 習(xí)題 電路圖 解 列 KCL 、 KVL 方程 為 ? ????????????????0j1055j52121IIII 整理得 ? ? 05j5511 ??????? ?????? II ? ? j555j5 1 ???? ?I A901j55 5j51 ?????????I 6 3 . 4 6 A1 . 1 12 ?????? ?? II 利用支路電流法求圖 所示電路的電流 ?I 。 (a) 電路 (b) 相量模型 圖 習(xí)題 電路圖 解 將時(shí)域模型轉(zhuǎn)化為相量模型如圖（ b）所示。 圖 習(xí)題 電路圖 解 (a) 222221 ?????? III (b) A11221 ????? III (c) ???? UUU (d) V11221 ????? UUU 求圖 所示電路 ab 端的等效阻抗 Z 及導(dǎo)納 Y 。 圖 習(xí)題 圖 解 列 KVL 方程，有 21S uuu ?? 相量關(guān)系為 ： 2mm1m ??? ?? UUU S ??????? 0930154 V1 2 4 .6 .4 6 ??????? 所以 ? ?V4 .6 812s in6 .0 8S ??? tu 。 正弦電流和電壓分別為 （ 1） V)60 4s in (23 o1 ?? tu （ 2） V)75 4co s(52 ??? tu （ 3） A)90 4sin(2 o1 ??? ti (4) V)4