資訊推薦

• 【題組】(二)此變壓器二次側輸出額定電壓，供應功率因數 0.8 落後的額定負載時，效率及電壓調整率為何？（8 分）
• 三、額定 30 kW、120 V 之他激式直流發電機，電樞電阻Ra= 0.04 Ω，當激磁電流 If = 1.5 A，轉速為 2400 rpm 時，此發電機的開路電壓為120V。若將此電機當作直流電動
• 【題組】(二)計算此電動機之電樞電壓 Ea、電樞電流 Ia、及輸出轉矩 τ。（15 分）
• 四、一部三相、2300 V、60 Hz、12 極、Y 接之同步電動機，每相同步電抗為4.5 Ω，此電動機接至 2300 V 之無窮母線，汲取250 A功率因數0.8落後之電流，忽略電樞電阻及機械損失。
• 【題組】(二)計算此電動機可緩慢加載而不失步的最大輸出機械功率。（10 分）
• 五、一部額定 460 V、60 Hz、20 kW 之三相 4 極感應電動機，從 460 V、60 Hz電源汲取 25 A 電流，功率因數 0.9 落後。若鐵損為 0.9 kW，定子銅損為 1.1 kW
• 【題組】(二)氣隙功率Pag。
• 【題組】(三)轉差率 s。
• 【題組】(四)輸出機械功率。
• 2. 硼的原子序為5，平均分子量為10.81。試問關於硼及其化合物:【題組】(1)硼是否具有同位素？_________ (填是或否) (2分)(A)O(B)X
• 【題組】(二)兩種方法的標準差在 95%信賴水準時是否有顯著差異。（8 分）
• 二、芬普尼（Fipronil, FM 437.15）是一種廣效殺蟲劑，用於農業、居家及寵物用藥，進行液相層析質譜儀分析市售雞蛋樣品中芬普尼之殘留，請問欲配製 43.7 μg 芬普尼溶於 250 毫升（
• 【題組】(二) ppb
• 【題組】(三)轉換為微莫耳濃度（micromolarity, μM）
• 2 There were 198 ________on the airplane that was attacked last week. No one survived.(A) passages (
• 3 Janet has been depressed since she lost her job, but we believe she'll feel better________whe
• 4 According to some studies, children with no brothers and sisters are inclined to be________ . They
• 5 When Sarah was sick, her loving father tried to________ by singing to her.(A) heat her up (B) chee
• 6 Most people blame the governemt for the country’s current economic ________ .(A) advantage (B) cri
• 7 According to the________, one in ten people may have a tendency to drink too much liquor over the
• 8 Let’s________ a break when we finish this exercise.(A) make (B) do (C) set (D) take
• 9 Because their gum leaf diet does not give them much ________, koalas sleep a lot.(A) comfort (B) e
• 10 Anita and her twin sister Louisa pursued very different careers: she became a teacher,________ he
• 11 Talking with your mouth full________not a polite thing to do.(A) was (B) are (C) is (D) were
• 12 A doctor________to Melanie and bandaged her hands.(A) talked (B) who talks (C) that talks (D) tal