【单选题】
感应电动机的额定功率___从电源吸收的总功率。
A. 大于;
B. 小于;
C. 等于;
D. 变化的。
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答案
B
解析
暂无解析
相关试题
【单选题】
电动机铭牌上的“温升”指的是___的允许温升。
A. 定子绕组;
B. 定子铁芯;
C. 转子;
D. 冷却风温。
【单选题】
异步电动机在起动时的定子电流约为额定电流的___。
A. 1~4倍;
B. 3~5倍;
C. 4~7倍;
D. 7~10倍。
【单选题】
整流柜退出运行时,应先拉开该组整流柜脉冲开关,检查输出电流指示零位后,再拉开___。
A. 交流侧刀闸;
B. 直流侧刀闸;
C. 交、直流侧刀闸;
D. 脉冲开关。
【单选题】
发电机并、解列时开关三相不同期分、合闸,将在主变中性点产生___。
A. 过负荷;
B. 过电压;
C. 过电流;
D. 火花。
【单选题】
正常运行方式下2号主变高压侧中性点接地方式为___。
A. 直接接地;
B. 间隙接地;
C. 经电阻接地;
D. 不接地。
【单选题】
在正常运行条件下,机变组___保护A、B柜均不投。
A. 间隙接地;
B. 定子接地;
C. 转子一点接地;
D. 转子两点接地。
【单选题】
发电机中性点接地方式为___。
A. 直接接地;
B. 经电阻接地;
C. 经消弧线圈接;
D. 不接地。
【单选题】
发电机机内氢压应___定子冷却水压。
A. 高于;
B. 低于;
C. 等于;
D. 不一定。
【单选题】
变高压侧中性点接地方式为___。
A. 直接接地;
B. 间隙接地;
C. 经电阻接地;
D. 不接地。
【单选题】
修后发变组并网时,为瞬间切除故障, ___保护可投跳闸.但在带负荷前应根据继电人员要求 ,将出口压板断开,以便进行负荷电流校验。
A. 起停机;
B. 误上电;
C. 差动;
D. 匝间。
【单选题】
在切换压板时,应防止___,压板断开后不应横放,应朝下拧紧。
A. 接地;
B. 摩擦;
C. 互相碰连;
D. 过慢。
【单选题】
异步电动机的熔断器的定值一般按照电动机的___来整定。
A. 额定电流的1倍;
B. 启动电流值;
C. 额定电流的1.5 ~ 2.5倍;
D. 额定电流的5倍。
【单选题】
整流柜退出运行时,应先拉开该组整流柜的___。
A. 交流刀闸;
B. 直流刀闸;
C. 风机开关;
D. 脉冲开关。
【单选题】
电动机在额定功率运行时,三相的不平衡电流不得超过额定电流的___。
A. 2%;
B. 5%;
C. 10%;
D. 20%。
【单选题】
三相异步电动机接通电源后启动不起来,有强烈的“嗡嗡”声是由于___。
A. 电源一相断开;
B. 电源电压过低;
C. 定子绕组有短路 ;
D. 原因不定。
【单选题】
发现电动机冒烟时,应___。
A. 立即停止电动机运行;
B. 汇报值长、班长后停止运行;
C. 使用灭火器迅速灭火;
D. 立即切换设备。
【单选题】
在正常运行条件下,定子绕组温度应不超过___。
A. 90℃;
B. 100℃;
C. 110℃;
D. 115℃。
【单选题】
系统频率过低时应增加电网上与之并列的发电机___。
A. 有功功率;
B. 无功功率;
C. 感性功率;
D. 容性功率。
【单选题】
转动设备的电动机被水淹没,应___。
A. 申请停运;
B. 紧急停止运行;
C. 视情况而定;
D. 可以运行。
【单选题】
发电机转子铁芯采用___冷却。
A. 氢气;
B. 水;
C. 双水;
D. 水氢。
【单选题】
发电机定子电压低于额定值的95%时,定子电流长期允许的数值不得超过额定值的___。
A. 95%;
B. 100%;
C. 105%;
D. 110%。
【单选题】
新投运的变压器或更换绕组后的变压器,应从高压侧在额定电压下空载合闸___次,以检查励磁涌流下的继电保护动作情况。
A. 3;
B. 4;
C. 5;
D. 6。
【单选题】
断路器的额定开断容量可用___表示。
A. 额定开断容量=额定电压×额定开断电流;
B. 额定开断容量=额定电压×额定开断电流;
C. 额定开断容量=额定电压×极限开断电流;
D. 额定开断容量=额定电压×极限开断电流。
【单选题】
真空断路器的灭弧介质是___。
A. 油;
B. SF6;
C. 真空;
D. 空气。
【单选题】
真空断路器的触头常常采用___触头。
A. 桥式;
B. 指形;
C. 对接式;
D. 插入。
【单选题】
6kV厂用工作电源切换至备用电源后,应在___上将快切装置复位。
A. DCS;
B. 快切装置;
C. 工作电源开关;
D. 备用电源开关。
【单选题】
电缆的运行电压不得超过额定电压的___。
A. 5%;
B. 10%;
C. 15%;
D. 20%。
【单选题】
发电机机内定冷水温度应___冷氢温度。
A. 低于;
B. 高于;
C. 等于;
D. 不一定。
【单选题】
发电机定子铁芯采用___冷却。
A. 氢气;
B. 水;
C. 双水;
D. 水氢。
【单选题】
当发电机的定子线棒层间温差达到___在确认测温元件正常的情况下应停机处理。
A. 8℃;
B. 10℃;
C. 12℃;
D. 14℃。
【单选题】
6kV电动机定子线圈对地绝缘电阻值每千伏不得低于___。
A. 0.5MΩ;
B. 1MΩ;
C. 6MΩ;
D. 2500MΩ。
【单选题】
励磁系统强励倍数等于___倍,允许强励时间为10s。
A. 1.1;
B. 1.5;
C. 2;
D. 3。
【单选题】
对有载调压装置进行远方调压操作时,就地必须派专人监视,以防___。
A. 分接头过热;
B. 操作失控;
C. 产生火花;
D. 开关跳闸。
【单选题】
厂用电压降低时,若要不降低厂用电动机的出力,则电动机电流会___。
A. 降低;
B. 显著增加;
C. 保持不变;
D. 摆动。
【单选题】
变压器的调压分接头装置都装在高压侧,原因是高压侧线圈中流过的___,分接装置因接触电阻引起的( C )。
A. 电流小;
B. 电流大;
C. 发热量小;
D. 发热量大。
【单选题】
当发电机任一槽内线棒层间温度大于___且出水温度超过85℃时,在确认测温元件正常的情况下应停机处理。
A. 85℃;
B. 90℃;
C. 95℃;
D. 100℃。
【单选题】
当___时,柴油发电机自启动。
A. 机组跳闸;
B. 保安A、B段母线均失压或欠压;
C. 保安电源高电压;
D. 保安电源进线过电流未动作。
【单选题】
当UPS整流器输出电压低于___、直流输入电压低于( A )、逆变器故障、旁路电源故障及冷却风机故障时,UPS均有报警信号。
A. 240V 210V;
B. 220V 220V;
C. 300V 220V;
D. 220V 220V。
【单选题】
柴油发电机组的控制起动、保护、测量、信号系统采用直流电压,断路器控制、操作及其信号采用机组自身提供的直流___电压。
A. 12V;
B. 24V;
C. 36V;
D. 220V。
【单选题】
柴油发电机组备用状态下其的控制方式在应在___位置。
A. 手动;
B. 2自动;
C. 就地;
D. 远方。
推荐试题
【单选题】
8)The breakdown of large molecules to smaller ones is called___
A. respiration
B. anabolism
C. catabolism
D. absorption
【单选题】
9) Which of the following descriptions about the characteristics of nervous regulation is wrong?___
A. It responds fast
B. It acts exactly
C. It responds slowly.D.
D. uration is short
【单选题】
10)Which of the following descriptions about the control of body function is wrong?___
A. Homeostasis is kept by feedback control.
B. Negative feedback minimizes the changes, leading to stability.
C. Positive feedback is not useful.
D. Feed-forward makes human body foresee and adapt itself to the environment promptly.
【单选题】
(1)Which of the following parts of knowledge of drugs should be included in pharmacology?___
A. The effects of drugs on man
B. The correlation of biological activity with chemical structure
C. The history, source, physical and chemical properties, compounding, biochemical and physiologicaleffects, mechanisms of action, absorption, distrilbution, biotransformation and excretion.
D. The prevention, recognition, and treatment of drug poisonings
【单选题】
(2)Which of the following is what a clinician is primarily interested in according to the text?___
A. Drugs which can be reasonably limited to those aspects that provide the basis for their rational clinical use
B. Chemical agents that are not used in therapy but are commonly responsible for household and industrial poisoning as well as environmental pollution
C. Drugs which are useful in the prevention,diagnosis and treatment of human disease,or in the prevention of pregnancy.
D. rugs which are useful in the prevention, diagnosis and treatment of human disease, or in the prevention of pregnancy.
【单选题】
(3)Why was the physician not interested in pharmacognosy?___
A. He didn't have to select the proper plants for his prescription
B. He had a broad botanical knowledge
C. Fewer drugs were obtained from natural sources
D. Natural drugs had little difference with synthetic ones
【单选题】
(4)Which of the following is the best way of studying pharmacology for medical students and practitioners?___
A. to have a broad botanical knowledge
B. to select a plant and its preparation
C. to have the ability to purify natural plants
D. to have curiosity that stimulates them to learn about sources of drugs
【单选题】
(5)What are the tasks related to medicines almost complete!y delegated to the pharmacists now?___
A. the physical and chemical properties of medicines
B. the preparing, compounding, and dispensing of medicines
C. dosage forms of medicines available
D. the therapeutic and other uses of medicines
【单选题】
(6) What is a main unique aspect of pharmacodynamics?___
A. Pharmacodynamics is an experimental medical science
B. Pharmacodynamics is focused on the characteristics of drugs
C. Pharmacodynamics borrows freely from both the subject matter and the experimenta techniques of physiology, biochemistry, microbiology, genetics and pathology
D. Pharmacodynamics correlates the entire field of preclinical medicine
【单选题】
7) What time of history does pharmacodynamics date back to?___
A. the second half of the seventeenth century
B. the second half of the eighteenth century
C. the second half of the nineteenth century
D. the second half of the twentieth century
【单选题】
8)What does the research on pharmacodynamics focus on?___
A. study of clinical effect of drugs
B. study of the process of drugs in the body
C. study of the effect and the mechanism of drugs on the body
D. study of the correlation of the actions and effects of drugs with their chemical structure
【单选题】
(9)Which of the following is true when drugs are selected?___
A. It has to be based in part on legal reasons.
B. It has to be based in part on ethical reasons.
C. It has to be based in part on the pharmacological evaluation in man
D. It has to be based in part on the pharmacological evaluation in animals
【单选题】
(10)Why are chemotherapeutic agents useful in therapy?___
A. They stimulate or depress biochemical or physiological function in man in a sufficiently reproducible manner to provide relief of symptoms or, ideally, to alter favorably the course of disease
B. They can produce desired effects with only tolerable undesired effects
C. They have only minimal effects on man but can destroy or eliminate parasites
D. The selectivity of their effects is one of their most important characteristics
【单选题】
1)H. Mario Geysen initially used parallel synthesis as a quick way to identify which small_____ of any given large protein bound to an antibody.___
A. division
B. pieces
C. part
D. fragment
【单选题】
2)Chemists often start a combinatorial synthesis by attaching the first set of building blocks_____ to microscopic beads made of polystyrene.___
A. solid
B. inert
C. soft
D. active
【单选题】
3)The chemical reactions required to link compounds to the beads and later to detach them____ to the synthesis proces.___
A. induce complications
B. make easy
C. introduce complications
D. introduce easy
【单选题】
4)In a parallel synthesis, all the products are_____ separately in their own reaction vessels.___
A. combined
B. assembled
C. joined
D. assorted
【单选题】
(5)In many laboratories today, robots assist with the routine work of parallel synthesis, such as small___ amounts of reactive molecules into the appropriate wells.___
A. sending
B. transporting
C. delivering
D. giving
【单选题】
(6)Scientists can pull out from the mixture the beads that bear biologically active molecules and then,using sensitive detection techniques,___ the molecular makeup of the compound attached.___
A. determine
B. make sure
C. find
D. search
【单选题】
(7)Most pharmaceutical companies today continue to___ parallel synthesis. Which of the following is not appropriate to be filled in the blank?___
A. count in
B. count on
C. depend on
D. rely on
【单选题】
(8)Once they identify a promising substance, they___ make many one-at-a-time modifications to the structure.___
A. laboriously
B. hardly
C. easy
D. effectively
【单选题】
(9)Often these procedures yield a compound having acceptable___ and safety.___
A. strength
B. effect
C. potency
D. effort
【单选题】
10)In many laboratories today, robots___ the routine work of parallel synthesis.___
A. help
B. assist with
C. assist in
D. assist to
【单选题】
(1)Pharmaceutics is an interdisciplinary subject involving___
A. formulation, manufacturing, physical pharmacy, and biopharmaceutics
B. manufacturing
C. physical pharmacy
D. biopharmaceutics
【单选题】
(2)Formulation is about the design, development and evaluation of dosage forms,___
A. discovery of novel drugs
B. analytical methods
C. drug delivery systems and manufacturing process
D. dosing regimen
【单选题】
(3)Biopharmaceutics mainly studies the in vivo process of drugs and metabolites in humans, animals and tissue culture, which specifically involves___
A. absorption and distribution
B. absorption, distribution, metabolism, and excretion
C. metabolism and excretion
D. absorption and excretion
【单选题】
(4)Regarding the definition of bioavailability(BA), BA is related to___
A. total plasma drug concentration only
B. unbound drug concentration in the plasma
C. unbound drug concentration at the target site
D. total plasma drug concentration, and the administered drug dose
【单选题】
(5)Plasma drug concentration is affected by following factors such as___
A. rate of absorption
B. rate and extent of distribution
C. rate ofeli Imination
D. all ofabove
【单选题】
6)Which of the following routes of administration will involve the absorption of drugs?___
A. i.v.injection
B. i.v.infusion
C. Subcutaneous injection, transdermal and oral
D. None of above
【单选题】
(7)Which of the following factors may influence the time course of a drug in the plasma and hence at its site of action?___
A. Food
B. Disease state
C. Route of administration
D. All of above
【单选题】
(8)Please identify the potential biological barriers for an orally administered tablet to be absorbed into the systemic circulation___
A. Sk d dermis
B. Gastrointestinal epithelium
C. Oral mucosal membrane
D. All of above
【单选题】
(9) Given the same administration dose, which of the following will likely result in varying bioavailabilities for the same drug administered to the same person? ___
A. tablets (p.o. )vs. solutions(p0.)
B. solutions for injection(i v )vs oral solutions(p0.)
C. coated tablets (p.0. )vs hard gelatin capsules(p0.)
D. All ofabove
【单选题】
(10)Which of the following statements is true?___
A. Bioavailability is only related to the administered dose and the total drug concentration in the blood circulation.
B. Plasma protein binding does not affect the bioavailability of a specific drug.
C. A given drug in different dosage forms may show differences in bioavailability if given by the same route.
D. Biopharmaceutical studies do not involve animal experiment.
【判断题】
Much of our present physiological knowledge has been found from the experiments and studies on human beings.
A. 对
B. 错
【判断题】
Living cells break down glucose and fats to provide energy for other activities, which is called.
A. 对
B. 错
【判断题】
The right atriapumps deoxygenated blood to the lungs where it absorbs oxygen from the air.
A. 对
B. 错
【判断题】
The nervous system uses electrical signals to transmit information very rapidly to specific cells.
A. 对
B. 错
【判断题】
With the level of sodium increasing extracelular fruid. the cardiac muscle cells become too excitable and may contract.
A. 对
B. 错
【判断题】
A negative feedback loop is a control system that acts to maintain the level of some variables within a given range following a disturbance
A. 对
B. 错
【判断题】
(1)Pharmacodynamics, which is concerned with the study of the biochemical and physiological effects of drugs and their mechanisms of action, Is an experimental medical science.
A. 对
B. 错