(2007)晶體管單管放大電路如圖a)所示時(shí),其中電阻RB可調(diào),當(dāng)輸入U(xiǎn)i、輸出U0的波形如圖b)所示,輸出波形:()
A.出現(xiàn)了飽和失真,應(yīng)調(diào)大RB B.出現(xiàn)了飽和失真,應(yīng)調(diào)小RB C.出現(xiàn)了截止失真,應(yīng)調(diào)大RB D.出現(xiàn)了截止失真,應(yīng)調(diào)小RB
(2010)某晶體管放大電路的空載放大倍數(shù)Ak=-80、輸入電阻ri=1kΩ和輸出電阻ro=3kΩ,將信號(hào)源(uS=10sinwtmV,RS=1kΩ)和負(fù)載(RL=5kΩ)接于該放大電路之后(見圖),負(fù)載電壓uo將為:()
A.-0.8sinwtV B.-0.5sinwtV C.-0.4sinwtV D.-0.25sinwtV
圖示的橋式整流電路中,已知Ui=100sinwt(V),Ri=1kΩ,若忽略二極管的正壓降和反相電流,負(fù)載電阻RL兩端的電壓平均值和電流平均值分別為:()
A.90V,90mA B.50V,100mA C.100V,100mA D.63.64V,63.64mA