如图所示电路中，电源电压u=311sin100
t（V），A、B间接有“220V 440W”的电暖宝、“220V 220W”的抽油烟机、交流电压表及保险丝。下列说法正确的是( )
A．交流电压表的示数为311V
B．电路要正常工作，保险丝的额定电流不能小于3
A
C．电暖宝发热功率是抽油烟机发热功率的2倍
D．1min抽油烟机消耗的电能为1.32×104J
答案：D
题目分析：电压表在交流电路中对应交流有效值，由于电源电压u=311sinl00πt(V)，故有效值为220V，所以A错误；因保险丝融化电流指有效值，电暖宝的电流
，油烟机的电流
，故保险丝的额定电流不能小于3A，所以B错误；电暖宝是纯电阻电路，故电功率等于发热功率440W，抽油烟机发热功率等于电功率减机械功率，即
，所以C错误；工作1 min抽油烟机消耗的电能为
，所以D正确。
| 阅读理解。 | ||||
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| 1. Person with _____ of experience is needed to head the bank. | ||||
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| A. at least two years B. twenty - five years C. three to six years D. more than five years | ||||
| 2. You should work for _____ if you become an editor of the magazine. | ||||
[ ] | ||||
| A. just nine hours a day B. no less than nine hours a day C. about ten hours a day D. less than 25 hours a week | ||||
| 3. If you want to be a teacher, you can _____ for more information. | ||||
[ ] | ||||
| A. call 567-1243 B. mail to< newbank@gol.com C. phone 432 - 3745 D. write to P. O. Box 213, Fairview | ||||
| 4. You need to have the experience of directing different activities to _____. | ||||
[ ] | ||||
| A. be an editor of the music magazine B. head a bank branch of Town Bank C. teach English in Language Centre D. work as a nurse in Child Care Centre | ||||
| 5. Which of the following is NOT true according to the passage? | ||||
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| A. Child Care Centre doesn't provide care for children of all ages. B. Teachers are wanted to teach English in the Language Centre. C. One with computer skills will be preferred to head the bank. D. Your own information is available for the position of the editor. |