在提高日光灯功率因数的实验中,并联电容后,总电流减小,有功功率( )。
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若线圈电阻为60Ω,当线圈外加200V正弦电压时,线圈中通过的电流为2A,则线圈的感抗为()Ω。
A. 60
B. 70.7
C. 80
D. 8606
能量转换过程不可逆的电路功率常称为有功功率功率;能量转换过程可逆的电路功率叫做无功功率功率;这两部分功率的总和称为视在功率。能量转换过程不可逆的电路功率常称为有功功率功率;能量转换过程可逆的电路功率叫做无功功率功率;这两部分功率的总和称为视在功率。()
A. 对
B. 错
Directions:In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once.A few months ago, I was down with a terrible cold which ended in a persistent bad cough. No matter how many different __1__ I tried, I still couldn’t get rid of the cough. Not only did it __2__ my teaching but also my life as a whole. Then one day after class, a student came up to me and __3__ traditional Chinese medicine. From her description, Chinese medicine sounded as if it had magic power that worked wonders. I was __4__ because I knew so little about it and have never tried it before. Eventually, my cough got so much __5__. that I couldn’t sleep at night, so I decided to give it a try. The Chinese doctor took my pulse and asked to see my tongue, both of which were new __6__ to me because they are both non-existent in Western medicine. Then the doctor gave me a scraping(刮)treatment known as ‘Gua Sha’. I was a little __7__ at first because he used a smooth edged tool to scrape the skin on my neck and shoulders. A few minutes later, the __8__ strokes started to produce a relieving effect and my body and mind began to __9__ deeper into relaxation. I didn’t feel any improvement in my condition in the first couple of days, but after a few more regular visits to the doctor, my cough started to __10__. Then, within a matter of weeks, it was completely gone!A) deepen E) lessen I)remedies M)temporaryB) experiences F) licenses J)scared N)trembleC) hesitant G) pressured K)sensitive O)worseD) inconvenience H) recommended L)sink
Section ADirections:In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the center. You may not use any of the words in the bank more than once.Have you ever used email to apologize to a colleague? Delivered a1to a subordinate (下属) with a voice-mail message? Flown by plane across the country just to deliver important news in person? The various communication options at our fingertips today can be good for 2and productivity—and at the same time very troublesome. With so many ways to communicate, how should a manager choose the one that's best— 3when the message to be delivered is bad or unwelcome news for the recipient? We've 4business communication consultants and etiquette (礼仪) experts to come up with the following guidelines for 5using the alternative ways of delivering difficult messages.First of all, choose how personal you want to be. A face-to-face communication is the most 6.Other choices, in descending order of personalization, are: a real-time phone call, a voice-mail message, a handwritten note, a typewritten letter, and the most 7 is email. Some of these may change order according to the 8 situation or your own preferences; for example, a handwritten note might seem more personal than voice-mail. How do you decide on the best choice for the difficult message you've got to deliver? “My 9 concern is: How can I soften or civilize this message?” says etiquette expert Dana Casperson. “ So when I apologize, I usually choose in-person first, or a phone conversation as my top alternative, and maybe a handwritten note next. Apologizing by email is something I now totally 10 .”