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工程與科技 大學

深綠色箭頭為什麼那邊要用Re1不能用Rπ 淺綠色螢光筆框框處為什麼有負號

如圖所示的三級串接負回授结 構,已知Emiz=100mA/V, ign = 20 mA/V, h% = 100 台 「如,試求其迴路增益。 [4] =r=h g = 100 100=1kQr₁ = h 電子學第四冊 IV V=0 A₁B₁ = 例題 14-8 =-Bz2 關於迴路增益 AA 測試,其相關電路 關閉信號源 其中,因Q 共射放大器為單向,該處的輸入電阻與其他無關,所以 最佳切開點選在「Q的輸入端」 R = R | = R || 1+h -V =100× R9kQ X T R1002 x x x 關聯V跳 vi I I x X 分析步驟: (a)切開閉迴路,切口看人等效電阻R=r=k2 10002 R R₂ + R₁₁ 5 5+13.75 R. 392 {R x101x -Rex(1+h)x R (b) 在響應端並聯一電阻R,並在測試端加上電壓源V ey (C)為了便於分析,於是先定義出各處等效電阻,加以整理,如圖所示 者,分別是: 1₁ I V V bi x 0.1 0.649 + 0.1 R T V co Re5kn 第十四章 負回授放大器 1- R₁ = ₁; +(1+h) (R₁ + R₂)||R₁|=5+ 101×00.649||0.1) rex 21 =13.75k2 (d)迴路增益分析:算法如下所列 Q方面:採用轉導放大,將信號轉成電流信號,再計算進化的 分流。不過,對於Q 而言,此分流為倒流者 Q方面:為射極追隨器,採用電流放大論點,再以分流觀念,計算 流入Q輸入端的電流 V R, www 6402 =h/g=100 20=5k$2. 1000 AI -=100|| 392 Q方面:為共基放大器,因輸入端有分支,遂用轉導放大觀念牙計 算出響應端電壓V RE Rask R₂ www 6402 (R+R) + R₂ Rea0.6k 1002 Re × 0.009×100X R 0.6k25R2 9×1 9+1 V 1000 Re ×R ×g (RRY = 291.27 說明: (1)此迴路增益A3與R 無關,這是因為不考慮r 之故。 (2)若考慮時,則將會干擾R 與此刻的人,而干擾的程度與尺, 門 1. 21 有關。因此,這時的迴路增益A 值將有關於R,所幸,此關聯 性甚弱,遂可忽略之。

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工程與科技 大學

各位大神 求解 拜託🙏🆘

CA 梁柱 一截面積是原來的兩倍 22. Two girders are made of the same material. Girder A is twice as long as girder B and Bo DE C B³ has a cross-sectional area that is twice as great. The ratio of the mass density of girder A to the mass density of girder B is: 質量密度 A) 4 B) 2 C) 1 D) 1/2 E) 1/4 29. During a short interval of time the speed v in m/s of an automobile is given by v=at² + bt³, where the time t is in seconds. The units of a and b are respectively: A) m-s²; m-s4 s³/m; s4/m dv=at+bt² B) C) m/s²; m/s³ D) m/s³; m/s4 E) m/s4; m/s5 34. The position y of a particle moving along the y axis depends on the time t according to the equation B) C) D) E) 質固定,体2倍 #%# 40. The coordinate of an object is given as a function of time by x = 7t-31², where x is in meters and t is in seconds. Its average velocity over the interval from t = 0 to t = 2 s is: A) 5 m/s X₂=0, X₁₂=14-12=2 B) -5 m/s 11 m/s C) D) -11 m/s (2-0)/2=1 E) -14.5 m/s 41. The coordinate of a particle in meters is given by x(t) = 16t-3.01³, where the time t is in seconds. The particle is momentarily at rest at t = A) 0.75 s A y = at -bt². The dimensions of the quantities a and b are respectively: A) L²/T, L³/T2 B) L/T², L²/T C) L/T, L/T² D) L³/T, T²/L E) none of these 1.3 s 5.3 s 7.3 s 9.3 s V(t) = 16-9+² =- [9t²-16) =-(3t+4) 13t-4) =+= 0.75 45. The velocity of an object is given as a function of time by v = 4t-312, where v is in m/s and t is in seconds. Its average velocity over the interval from t=0 to t=2 s: A) is 0 B) is -2 m/s C) is 2 m/s D) is -4 m/s E) cannot be calculated unless the initial position is given 49. A particle moves along the x axis according to the equation x = 61² where x is in meters and t is in seconds. Therefore: E B) C) D) E) A) the acceleration of the particle is 6 m/s² t cannot be negative the particle follows a parabolic path each second the velocity of the particle changes by 9.8 m/s none of the above

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