高中 解答

四個完全相同規格的喇叭同時發出聲響時,其音量會比單獨一個喇叭發出聲響時,高出約多少分貝 dB?(計算時可參考底下的對數表) log2 log3 log4 log5 log6 log8 log9 log10 0.301 0.477 0.602 0.699 0.778 0.903 0.954 1

如圖(十)所示為變壓器耦合串級放大電路,假設 A  100 、 A  26 dB 、 A  40 ,試求此電路之總 電壓增益為何? V1 V2 V3

有關放大器特性之敘述,下列何者錯誤?

如圖(九)所示之電路,假設電晶體   99 , V  0.7 V , 熱電壓 V 為 26 mV,試求將電晶體用小信號模型代入後之 BE T 交流電流增益 II 約為多少? o i

如圖(八)所示之電路,假設電晶體   90 ,熱電壓 V 為 26 mV, V  0.7 V ,試求輸入阻抗 Z 約為多少? T BE i

如圖(七)所示之電路,假設電晶體之   49 ,射極交流 電阻 r  8  ,試求電壓增益 VV 約為何? e o i

如圖(六)所示之電路,假設電晶體   100 , V  0.7 V , V  8 V ,試求 電阻 R 約為何? BE

如圖(五)所示之電路,假設電晶體工作於主動區,   80 且 V  0.7 V ,試求 基極電流 I 約為多少? BE

處於主動區的電晶體,假設集極電流為 14.7 mA,基極電流為 0.3 mA。請問共基極組態電流放大因數 α 為何?

有關雙極性電晶體 BJT 特性之敘述,下列何者錯誤?

如圖(四)所示之電路,已知 V (t)  220sin 377t V ,假設 L 與 L 的匝數相同,且 D 、 D 為理想二極體,試求 V 之平均電壓約 i 1 2 為多少? 1 2 o

如圖(三)所示之電路,若 V (t)  2  10sin 377t V ,且 D 為理想二 極體,試求 V 的中心電壓為何? i o

如圖(二)所示之電路,若 V 為 120sin 377t V ,且 D 、 D 為理 想二極體,試問下列敘述,何者正確? in 1 2

有關二極體特性的敘述,下列何者正確?

Which of the following words is closest in meaning to the word “range” in the last paragraph?

According to the passage, why are so many “ugly” works of art on display?

What’s this passage mainly about?

Where is Ani located?

When did Ani become a regional power?

What does the word “deteriorate” in the first paragraph probably mean?

What’s the passage mainly about?

Fiona: You look so pale! What happened? Irene: Did you hear the rumor about me? Andy said that I’m dating different boys at the same time. Fiona: Is he spreading it in school? Irene: I have no idea. I’m just worried how I’m going to face all my friends in school.

Amy: This morning, when I was withdrawing money in the bank, I saw a woman rushing in, wanting to take out all the money in her account. Tony: Was she being cheated? Amy: That’s right! She said someone called, saying that he had kidnapped her son. And she did hear a boy crying out loud on the other side of the phone. Tony: I believe the clerk in the bank asked her to go to the nursery to have a check first. Amy: You’re smart! That’s exactly what the woman was told to do.

Annie: What’s the matter with your sweater? It looks small on you. Jerry: I washed it in a washing machine, and it turned out like this. Annie: Didn’t you check the laundry symbol attached to the sweater? If the sweater is made of pure wool, you need to dry clean it. Jerry: Woops, ! The clerk warned me about that, and I just forgot it completely.