【判断题】
快切装置应保证只动作一次,在下次动作前,必须经人工复归
A. 对
B. 错
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答案
A
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纵联差动保护能快速、灵敏地切除保护范围内的相间短路故障,一般作为发电机和变压器的主保护
A. 对
B. 错
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电压互感器二次回路通电试验时,为防止由二次侧向一次侧反充电,只需将二次回路断开
A. 对
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在中性点直接接地系统中,零序电流互感器一般接在中性点的接地线上
A. 对
B. 错
【判断题】
正常运行中的电流互感器一次最大负荷不得超过1.2倍额定电流
A. 对
B. 错
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运行中的电流互感器过负荷,应立即停止运行
A. 对
B. 错
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运行中的电压互感器溢油时,应立即停止运行
A. 对
B. 错
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发电机—变压器接线,当变压器重瓦斯保护动作时,变压器各侧断路器将跳闸
A. 对
B. 错
【判断题】
距离保护的保护范围基本上不受运行方式及短路电流大小的影响
A. 对
B. 错
【判断题】
发电机转子回路发生一点接地时,定子三相电流将出现不平衡
A. 对
B. 错
【单选题】
火力发电厂的生产过程是把燃料的化学能转变为___。
A. 电能;
B. 机械能;
C. 热能;
D. 动能。
【单选题】
在火力发电厂的生产过程中,将燃料的化学能转变为热能的设备是___。
A. 锅炉;
B. 汽轮机;
C. 发电机;
D. 磨煤机。
【单选题】
火力发电厂的燃烧系统包括锅炉的燃烧部分及___、除灰系统等。
A. 煤场部分;
B. 输煤;
C. 汽机;
D. 化学。
【单选题】
煤的费用占燃煤电厂发电成本的___。
A. 50%左右;
B. 60%左右;
C. 70%左右;
D. 80% 以上。
【单选题】
火力发电厂是耗用燃料最多的企业,它的耗用量约占全国煤炭石油总产量的___。
A. 10%~20%;
B. 20%~25%;
C. 25%~30%;
D. 30%~40%。
【单选题】
火力发电厂是消耗二次能源(电力)的大户,在全国约占二次能源总数的___。
A. 3%~5%;
B. 5%~7%;
C. 7%~10%;
D. 10%~20%。
【单选题】
能量转换装置里使液压能转换为机械能的设备是___。
A. 油泵;
B. 换向阀;
C. 油电动机;
D. 油缸。
【单选题】
目前大中型火力发电厂对火车运输煤量的验收主要采用___计量。
A. 对煤车进行检尺;
B. 采用轨道衡;
C. 电子皮带秤;
D. 吃水表。
【单选题】
船舶运输煤量的验收一般有___种方法。
A. 1;
B. 2;
C. 3;
D. 4。
【单选题】
水路运输燃料的验收,一般是记录船的吃水线、水仓水位,检测___,查阅船舶设计数据及有关证件来确定燃料数量。
A. 水的密度;
B. 容积;
C. 皮重表;
D. 经验。
【单选题】
卸船机的五大机构是起升、开闭、小车、大车___。
A. 电缆卷筒机构;
B. 喷淋机构;
C. 拖缆机构;
D. 变幅机构。
【单选题】
煤的成分分析法有___。
A. 元素分析;
B. 工业分析;
C. 元素分析和工业分析;
D. 干燥基分析。
【单选题】
在规定条件下单位体积煤的质量称为煤的___。
A. 视密度;
B. 真密度;
C. 堆积密度;
D. 相对密度。
【单选题】
煤中所含元素量最多的是___。
A. 碳;
B. 氢;
C. 氧;
D. 水。
【单选题】
燃煤的碳化程度越高,___。
A. 挥发分越高;
B. 灰分越高;
C. 越不易自燃;
D. 越易自燃。
【单选题】
___是煤的组成成分中发热量最高的元素。
A. 碳;
B. 硫;
C. 氢;
D. 氧。
【单选题】
火力发电厂排出的烟气会造成大气污染,污染物主要是___。
A. 二氧化硫;
B. 二氧化碳;
C. 粉尘;
D. 氮氧化合物。
【单选题】
煤的燃烧是一个复杂的___变化过程。
A. 物理;
B. 化学;
C. 化合;
D. 物理和化学。
【单选题】
产生燃烧必须同时具备___个基本条件。
A. 5;
B. 4;
C. 3;
D. 2。
【单选题】
煤的发热量是煤在一定温度下完全燃烧时所释放出的___。
A. 物理热量;
B. 最大反应热;
C. 最小反应热;
D. 动能。
【单选题】
标准煤的发热量约是___M J/kg。
A. 29.3;
B. 7000;
C. 143;
D. 34。
【单选题】
当1kg 的燃料完全燃烧时,燃料的水分保持___时的发热量,称为高位发热量。
A. 蒸汽状态;
B. 液体状态;
C. 汽水混合状态;
D. 固定状态。
【单选题】
燃煤发热量增高对输煤系统___。
A. 没有影响;
B. 影响出力;
C. 不利;
D. 有利。
【单选题】
如锅炉负荷不变,煤的发热量降低,则输煤系统负担会___。
A. 减轻;
B. 加重;
C. 不变;
D. 无法确定。
【单选题】
挥发分含量对燃料燃烧特性影响很大,挥发分含量越高,越容易燃烧。___挥发分含量高,故容易燃烧。
A. 无烟煤;
B. 褐煤;
C. 贫煤;
D. 气煤。
【单选题】
挥发分是煤在___℃下隔绝空气加热7min , 煤中有机物发生分解而析出的气体和常温下的液体占试样前的质量百分比。
A. 200±10;
B. 900±10;
C. 700±10;
D. 800±l0
【单选题】
___高的煤易着火,燃烧稳定,但火焰温度低。
A. 挥发分;
B. 发热量;
C. 灰分;
D. 结焦性。
【单选题】
煤的着火特性主要取决于___的含量。
A. 水分;
B. 挥发分;
C. 灰分;
D. 碳。
【单选题】
低挥发分煤粉的着火温度可高达___℃。
A. l000;
B. 1100;
C. 1200;
D. 1300。
【单选题】
高挥发分煤粉的着火温度在___℃左右。
A. 500;
B. 600;
C. 800;
D. l000。
【单选题】
挥发分小于10%的煤称为___。
A. 无烟煤;
B. 烟煤;
C. 标准煤;
D. 贫煤。
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【单选题】
全党要不断增强党的_____,确保我们党永葆旺盛生命力和强大战斗力。
A. 群众领导力、思想组织力、社会凝聚力、政治向心力
B. 政治领导力、思想引领力、群众组织力、社会号召力
C. 政治领导力、思想引领力、群众发展力、社会号召力
D. 政治领导力、思想引领力、群众组织力、社会向心力
【单选题】
1___
A. She is going to have a lot of vanilla icecream.
B. She won the pelling competition at her school.
C. She is going to the state capital for a competition.
D. She spelled“exellence" correctly, but others didn't.
【单选题】
2___
A. His family moved to Sacramento to settle down.
B. His family bought him a new suit and a new tie.
C. He went to Sacramento for a spelling competition.
D. He won the first prize in the state spelling competition.
【单选题】
3___
A. Tomake him feel better after he lost the first prize.
B. To apologize for not buying him some ice cream.
C. To wish him good luck in the next competition.
D. To congratulate him on winning the frst prize.
【单选题】
4___
A. Red.
B. Blue.
C. Green.
D. Yellow.
【单选题】
1___
A. Superstitions and science.
B. Tips on how to have good luck.
C. Superstitions in the United States.
D. Rational and superstitious societies.
【单选题】
2___
A. Walking under a ladder.
B. Dreaming of a black cat.
C. Hanging a mirror in the house.
D. Stepping on one's own shadow.
【单选题】
3___
A. Because black cats look like witches.
B. Because black cats were thought to be witches.
C. Because black cats bring seven years of bad luck.
D. Because black cats are hard to notice in darkness.
【单选题】
4___
A. Breaking a mirror on purpose.
B. Catching a falling leaf on one's birthday.
C. Finding a penny on the ground and picking it up.
D. Dreaming of blowing out the candles in one blow.
【单选题】
1___
A. Read J. K. Rowling's first book.
B. Go to buy a new Harry Potter book.
C. Watch BBC news about J. K. Rowling.
D. Take her cousin to see a new Harry Potter movie.
【单选题】
2___
A. At a café.
B. Ona train.
C. At a cinema.
D. In a bookstore.
【单选题】
3___
A. She won't write any more books.
B. She will write more magic stories.
C. She hasn't said anything about her future plans.
D. She said she would work on more serious subjects.
【单选题】
4___
A. J. K. Rowling's secret.
B. J. K. Rowling's writing plan.
C. A new book by J. K. Rowling.
D. An interview with J. K. Rowling.
【单选题】
1___
A. He broke the milk bottle.
B. He fell down on the floor.
C. He made a mess inside the refrigerator.
D. He spilled the milk over the kichcn floor.
【单选题】
2___
A. Ѕhе gаvе hіm а lоng leсture.
B. She shouted at him in anger.
C. She enjoyed the wonderful mess.
D. She cleaned up the mess with him.
【单选题】
3___
A. How to do an experiment.
B. How to carry amilk bottle.
C. How to clean up spilled milk.
D. How to avoid making mistakes.
【单选题】
4___
A. Mistakes can become learning opportunities.
B. Mistakes are just like scientific experiments.
C. One should sometimes make mistakes.
D. One should try to avoid making mistakes.
【单选题】
1___
A. Because he likes the sunny weather,
B. Because he wants to challenge himself.
C. Because it can help solve his sleeping problem.
D. Because it can help him forget all his troubles.
【单选题】
2___
A. To go sailing.
B. To go surfing.
C. To go to the beach.
D. To go to her nephew's.
【单选题】
3___
A. Going to visit relatives.
B. Enjoying the warm sun on the beach.
C. Building sand castles with her niece and nephew.
D. Playing in the sand and jumping in the waves.
【单选题】
4___
A. Surfing in the sea.
B. Collecting seashells.
C. Building sand castles.
D. Jumping in thewaves.
【单选题】
1___
A. 89 percent.
B. 84 percent.
【单选题】
2___
A. People aged 16to 24.
B. People aged 25 to 34.
C. People aged 16 and over.
D. People aged 55 and over.
【单选题】
3___
A. People aged16 to 24 preferred listening to music most.
B. more popularB It was geting more andamong the Bish people.
C. Trwas the third most popular ativity among people aged 55 and over.
D. People aged 25 to 34 listened to musicmore often than those aged 16 to 24.
【单选题】
4___
A. Older people go out to pubs more often.
B. Younger people go to the cinema less frequently.
C. Older people spend more time reading and gardening.
D. Younger people spend less time visiting friends and family.
【单选题】
1___
A. 4 hours.
B. 2 hours.
C. 1.5 hours.
D. 45 minutes.
【单选题】
2___
A. At 8.
B. At 7.
C. At 6.
D. At 5.
【单选题】
3___
A. She can either read or rest a little on the train.
B. She can read and respond to emails on the train.
C. She can travel to many different parts of the city.
D. She can go shopping on her way home from work.
【单选题】
4___
A. He can take the train to the old part of the city.
B. He can save a lot of money when he takes the train.
C. He can save 20 minutes to go to work with the train.
D. Hecan take the train to the airpor insted of driving.
【单选题】
1___
A. About an hour.
B. More than an hour.
C. About half an hour.
D. More than one and a half hours.
【单选题】
2___
A. More and more Americans spend over an hour getting to work.
B. Over 10 percent of Americans spend less than an hour getting to work.
C. Only New York people spend more than 90 minutes getting to work.
D. Over 10 percent of Americans spend more than 90 minutes getting to work.
【单选题】
3___
A. Because gas prices are not high.
B. Because the commute is not tiring.
C. Because he can attend a better school.
D. Because he can have his favorite lifestyle.
【单选题】
4___
A. Traffic jams.
B. Expensive housing.
C. Poorer life quality.
D. A tiring and boring trip.
【单选题】
1___
A. She liked playing an interesting game.
B. She enjoyed seeing many of her old friends.
C. She enjoyed wearing her Halloween costume.
D. She liked the decorations in Jason's front yard.
【单选题】
2___
A. None of her friends likes Jason.
B. None of Jason's guests is young.
C. She wants to go to Linda's party.
D. She went to Jason's party last year.
【单选题】
3___
A. The party will last four hours.
B. Six people will attend the party.
C. They will have huge bags of candy.
D. They will play a new game called Guess Who"
【单选题】
4___
A. Go to Jason's party.
B. Go to Linda's party.
C. Attend both Jason's and Linda's parties.
D. Celebrate Halloween with her parents.
【单选题】
1___
A. Some stores offered bigger holiday discounts.
B. Some stores provided more choices of nightlife.
C. Some stores made efforts to attract young people.
D. Some stores opened much earlier than they used to.
【单选题】
2___
A. To attract young customers.
B. To beat other stores for sales.
C. To let people sleep late the next day.
D. To keep people stay up for the night.
【单选题】
3___
A. 24 percent.
B. 37 percent.
C. 9.5 percent.
D. 23.5 percent.