【单选题】
(30997)在使用GAC调速装置的康明斯发电车中，当运行中需换机或并车供电时，可以使用___来实现自动并车。
A. ESD5520
B. LSM201
C. SYC6714
D. 501K
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相关试题
【单选题】
(30998)发电车两机并车所需满足的条件是___。
A. 两机电频率相同
B. 两机电压值相同
C. 两机初相位相同
D. 以上都是
【单选题】
(30999)实现发电机组并车同期方式分为准同期和自同期两种，以下在叙述中不正确的是___。
A. 准同期指发电机并网前已励磁
B. 自同期法是指发电机并网后励磁
C. 自同期法并网速度快
D. 准同期法并网速度比自同期法快
【单选题】
(31000)发电机准同期法并车时常采用灯光并列法，康明斯发电车中采用___。
A. 灯光熄灭法
B. 灯光旋转法
C. 灯光交换法
D. 灯光不灭法
【单选题】
(31001)康明斯KTA-19G2柴油机的喷油器柱塞行程为___。
A. 7.72 mm
B. 7.69 mm
C. 7.36 mm
D. 7.81 mm
【单选题】
(31002)EFC电子调速器上转速降调整旋钮能调整转速降的范围是___。
A. 0～5％
B. 1％～3％
C. 2％～5％
D. 2％～3％
【单选题】
(31003)柱塞式喷油器开始喷油时的喷油压力取决于___。
A. 高压油腔中的燃油压力
B. 调压弹簧的预紧力
C. 喷油器的喷孔数
D. 喷油器的喷孔大小
【单选题】
(31004)康明斯KTA-19G2柴油机的喷油器柱塞是利用___冷却。
【单选题】
(31005)康明斯KTA-19G2柴油机的PT喷油器在喷完燃油后柱塞___。
A. 立即上升
B. 缓慢上升
C. 一直压于杯底
D. 较长一段时间压于杯底
【单选题】
(31006)康明斯发电车的冷却风机自动开启停控制器的控制温度分别是___。
A. 85 ℃，65 ℃
B. 90 ℃，75 ℃
C. 85 ℃，70 ℃
D. 80 ℃，60 ℃
【单选题】
(31007)康明斯发电车中，冷却风机高速电路中的热保护继电器的整定值为___。
A. 32 A
B. 38 A
C. 40 A
D. 45 A
【单选题】
(31008)发电车电气控制原理图中电压互感器文字符号用___标志。
【单选题】
(31009)中间继电器KA和接触器KM的最大区别是___。
A. KA用于直流控制，KM用于交流控制
B. KA用于交流控制，KM用于直流控制
C. KM中一般存在主触头和辅助触头之分，KA中没有主辅触头
D. KA中一般存在主触头和辅助触头之分，KM中没有主辅触头
【单选题】
(31010)画放大电路的交流通道时，电容和直流电源可分别认为是___。
A. 开路，短路
B. 短路，开路
C. 开路，开路
D. 短路，短路
【单选题】
(31011)圆柱度误差是指___。
A. 气缸中垂直于气缸轴线的同一截面上，所测得最大直径与最小直径差值之半
B. 气缸中垂直于气缸轴线的两个截面上，所测得最大直径与最小直径差值之半
C. 气缸中垂直于气缸轴线的同一截面上，所测得最大半径与最小半径差值之半
D. 气缸中垂直于气缸轴线的两个截面上，所测得最大半径与最小半径差值之半请输入内容
【单选题】
(31012)基本偏差为一定的轴的公差带，与不同基本偏差的孔的公差带形成各种配合的一种制度叫___。
A. 基轴制
B. 基孔制
C. 基准制
D. 其它三项所述都不是
【单选题】
(31013)对偏差与公差之关系，下列说法正确的是___。
A. 实际偏差逾大，公差逾大
B. 上偏差逾大，公差逾大
C. 上、下偏差逾大，公差逾大
D. 上、下偏差之差的绝对值逾大，公差逾大
【单选题】
(31014)关于零件草图，下面说法中，正确的是___。
A. 零件草图用徒手目测绘制而成
B. 零件草图的尺寸标准不必齐全
C. 一个零件表达方式，其确定原则是读图方便
D. 零件的破坏损缺陷必须再草图上画出
【单选题】
(31015)机械图样中，标准圆角R8 max 的表示意义是___。
A. 此圆角最大8 mm，最小为0 mm
B. 此圆角最大8 mm，最小不限制
C. 此圆角最小8 mm，最大不限制
D. 此圆角只能为8 mm，不能加大也不能缩小
【单选题】
(31016)基本偏差是___。
A. 上偏差
B. 下偏差
C. 上偏差和下偏差
D. 上偏差或下偏差
【单选题】
(31017)最大极限尺寸___基本尺寸。
A. 大于
B. 小于
C. 等于
D. 大于、小于或等于
【单选题】
(31018)滚动轴承内径尺寸公差的___。
A. 上偏差为负值
B. 下偏差为负值
C. 下偏差为正值
D. 上偏差为正值
【单选题】
(31019)互换性的零件应是___。
A. 相同规格的零件
B. 不同规格的零件
C. 相互配合的零件的零件
D. 具有相同公差的零件
【单选题】
(31020)交流电路测量和自动保护中，使用电流互感器的目的是___。
A. 既可扩大量程，又可降低测量设备及保护设备的绝缘等级
B. 为了安全
C. 为了扩大量程
D. 增加测量保护精度请输入内容
【单选题】
(31021)在三相四线制电路的中线上，不准安装开关和熔断器的原因是___。
A. 中线上没有电流
B. 开关接通或断开对电路无影响
C. 安装开关和熔断器会降低中线的机械强度
D. 开关断开或熔断器熔断后，三相不对称负载承受三相不对称电压的作用，无法正常工作，严重时会烧毁负载
【单选题】
(31022)使用电流互感器和电压互感器时，其二次绕组应分别___接入被测电路之中。
A. 串联、并联
B. 并联、串联
C. 串联、串联
D. 并联、并联
【单选题】
(31023)零件测绘时，被测要素遵守___原则时，其实际形状遵守的理想边界为最大实体边界。
A. 最大实体
B. 最小实体
C. 包容
D. 独立
【单选题】
(31024)同一组蓄电池中各个蓄电池的容量互差不得超过___。
A. 5％
B. 10％
C. 15％
D. 20％
【单选题】
(31025)气门间隙过小不会引起___。
A. 影响进、排气门的启闭定时
B. 发动机最大功率下降
C. 柴油机发出强烈的噪声
D. 压缩时漏气，压缩终点压力、温度降低
【单选题】
(31026)康明斯KTA-19G2柴油机进气推杆顶弯将会造成___。
A. 气门关闭不严
B. 进气门间隙偏大
C. 进气摇臂受力增大
D. 其它三项所述都不对
【单选题】
(31027)发动机气门间隙过大，使气门脚发出异响，可用___进行辅助判断。
【单选题】
(31028)KTA-19G2型柴油机进排气门间隙分别是___。
A. 0.3 mm，0.35 mm
B. 0.35 mm，0.35 mm
C. 0.35 mm，0.40 mm
D. 0.36 mm，0.69 mm
【单选题】
(31029)在调整康明斯KTA-19G2柴油机气门间隙时，若指示标志C对准最高点时，要调整___全部气门间隙。
A. 1缸或6缸
B. 2缸或5缸
C. 3缸或4缸
D. 2缸和5缸
【单选题】
(31030)用千分表法调整康明斯KTA-19G2柴油机喷油器柱塞行程时，若5号缸可以调气门间隙，则___可以调喷油器柱塞行程。
【单选题】
(31031)发动机气门间隙调整可分为热调和冷调，其中冷调是指发动机机不工作至少4 h或水温油温不超过___ 时调整。
A. 90 ℃
B. 85 ℃
C. 65 ℃
D. 60 ℃
【单选题】
(31032)康明斯KTA-19G2柴油机中，顺时针拧动喷油器塞调整螺钉，将使相应的喷油器柱塞行程___。
A. 变大
B. 变小
C. 不变
D. 变大或变小
【单选题】
(31033)若康明斯KTA-19G2柴油机中使用的PT喷油器上部密封圈损坏将造成___。
A. 每循环喷油量下降
B. 喷油压力变大
C. 喷油雾化不良
D. 其它三项所述都不对
【单选题】
(31034)康明斯KTA-19G2柴油机中使用的PT喷油器工作时绝大多数时间是处于___阶段。
A. 量油
B. 喷油
C. 旁通回油
D. 预喷
【单选题】
(31035)康明斯KTA-19G2柴油机的喷油器柱塞行程若调整偏大，将造成___。
A. 喷油器积炭
B. 摇臂折断
C. 供油推杆弯曲
D. 其它三项所述都可能
【单选题】
(31036)喷油器针阀圆柱密封面磨损产生的主要影响是___。
A. 针阀圆柱面润滑性变好
B. 针阀不易卡死
C. 各缸喷油不均，转速不稳
D. 针阀撞击加重
【单选题】
(31037)用千分表法调整康明斯KTA-19G2柴油机喷油器柱塞行程时，相应气缸的喷油器柱塞处于___。
A. 杯底位
B. 最高位
C. 上升阶段
D. 下降阶段
推荐试题
【单选题】
Higher education in the United States began with the founding of
A. A. Yale University
B. B. Harvard University
C. C. Princeton University
D. D. New York University
【单选题】
Of the following subjects, are NOT offered to elementary school students.
A. A. mathematics and languages
B. B. politics and business education
C. C. science and social studies
D. D. music and physical education
【单选题】
Formal education in the United States consists of , secondary and higher education.
A. A. kindergarten
B. B. public
C. C. elementary
D. D. private
【单选题】
At present, U. S. exports account for of the world’s total.
A. A. 10%
B. B. 15%
C. C. 20%
D. D. 25%
【单选题】
is not one of the three giants in American automobile industry.
A. A. Ford
B. B. General Motors
C. C. Chrysler
D. D. American Motors
【单选题】
The following statements are all true except .
A. A. Agribusinesses reflect the big, corporate nature of many farm enterprises.
B. B. Agribusinesses maintain a balanced trade pattern between agricultural imports and exports.
C. C. Agribusinesses range from one-family corporations to multinational firms.
D. D. Agribusinesses include a variety of farm businesses and structures.
【单选题】
About of American crops are for export.
A. A. half
B. B. one third
C. C. one fourth
D. D. one fifth
【单选题】
President Johnson tried to build a “Great Society” by introducing various programs like the following except .
A. A. Medicare
B. B. Food Stamps
C. C. Education Initiatives
D. D. Unemployment Pension
【单选题】
The following inventions took place during the “second indThe following inventions took place during the “second industrial revolution” except .
A. A. typewriter
B. B. telephone
C. C. electric light
D. D. refrigerator
【单选题】
The first National Bank of the United States was established with the urge of .
A. A. George Washington
B. B. Thomas Jefferson
C. C. Andrew Jackson
D. D. Alexander Hamilton
【单选题】
Chartered companies were NOT granted the by the British King or Queen.
A. A. political authority
B. B. economic rights
C. C. judicial authority
D. D. diplomatic authority
【单选题】
The modern American economy progressed from to , and eventually, to .
A. A. colonial economy, handcraft economy, industrial economy
B. B. farming economy, handcraft economy, industrial economy
C. C. colonial economy, farming economy, industrial economy
D. D. handcraft economy, farming economy, industrial economy
【单选题】
America produces a major portion of the world’s products in the following fields except .
A. A. machinery
B. B. automobiles
C. C. ore
D. D. chemicals
【单选题】
The President is directly voted into office by .
A. A. all citizens of America
B. B. the citizens over 18 years old
C. C. electors elected by the voters
D. D. the senators and representatives
【单选题】
The Supreme Court is composed of justices.
A. A. six
B. B. seven
C. C. eight
D. D. nine
【单选题】
The terms for a Senator and Representative are and years respectively.
A. A. two, four
B. B. two, three
C. C. two, six
D. D. six, two
【单选题】
According to the Constitution, a candidate for President must be .
A. A. at least 35 years old
B. B. at least a 14 years’ resident of the United States
C. C. born in America
D. D. all of the above
【单选题】
The following except are all powers of the President.
A. A. vetoing any bills passed by Congress
B. B. appointing federal judges when vacancies occur
C. C. making laws
D. D. issuing executive orders
【单选题】
All the following except cannot make legislative proposal.
A. A. the Senator
B. B. the Representative
C. C. the Secretary of State
D. D. the President
【单选题】
The following except are guaranteed in the Bill of Rights.
A. A. freedom of religion
B. B. the right to get into people’s house by police
C. C. freedom of speech and of press
D. D. the right to own one’s weapon if one wishes
【单选题】
The Bill of Rights .
A. A. defines the rights of Congress and the rights of the President
B. B. guarantees citizens of the United States specific individual rights and freedoms
C. C. is part of the Declaration of Independence
D. D. has no relationship with the Constitution
【单选题】
The Constitution of the United States .
A. A. gives the most power to Congress
B. B. gives the most power to the President
C. C. tries to give each branch enough power to balance the others
D. D. gives the most power to the Supreme Court
【单选题】
The U. S. Constitution came into effect in .
A. A. 1787
B. B. 1789
C. C. 1791
D. D. 1793
【单选题】
The Vietnam War was a long-time suffering for Americans, and it continued throughout the terms of Presidents .
A. A. Johnson, Nixon and Ford
B. B. Truman, Eisenhower and Kennedy
C. C. Kennedy, Johnson and Nixon
D. D. Eisenhower, Kennedy and Johnson
【单选题】
President applied New Deal to deal with the problems of the Great Depression.
A. A. Wilson
B. B. Truman
C. C. Roosevelt
D. D. Kennedy
【单选题】
The policy of the United States was at the beginning of the two world wars.
A. A. neutrality
B. B. full involvement
C. C. partial involvement
D. D. appeasement
【单选题】
Abraham Lincoln issued to grant freedom to all slaves.
A. A. Declaration of Independence
B. B. Constitution
C. C. Emancipation Proclamation
D. D. Bill of Rights
【单选题】
In May 1775, was held in Philadelphia and began to assume the functions of a national government.
A. A. the First Continental Congress
B. B. the Second Continental Congress
C. C. the Boston Tea Party
D. D. the Congress of Confederation
【单选题】
The first shots of the American dependence were fired in .
A. A. Concord
B. B. Lexington
C. C. Philadelphia
D. D. Boston
【单选题】
“No taxation without representation” was the rallying slogan of .
A. A. the settlers of Virginia
B. B. the people of Pennsylvania
C. C. the colonists in New England
D. D. the people of the 13 colonies
【单选题】
The Seven Years’ War occurred between the .
A. A. French and American Indians
B. B. French and Spaniards
C. C. French and British
D. D. British and American Indians
【单选题】
Pilgrim Fathers are a group of who came to America to avoid persecution in England.
A. A. Protestants
B. B. Puritans
C. C. Catholics
D. D. Christians
【单选题】
The first successful English colony in North America was founded at in .
A. A. Jamestown, Louisiana
B. B. Boston, Massachusetts
C. C. Jamestown, Virginia
D. D. Plymouth, Georgia
【单选题】
The characteristic of dominant American culture is .
A. A. English-speaking, northern European, Roman Catholic and middle-class
B. B. English-speaking, western European, Roman Catholic and upper-class
C. C. English-speaking, northern European, Protestant and upper-class
D. D. English-speaking, western European, Protestant and middle-class
【单选题】
The ImmiWar of Ingrants Act of 1924 restricted the further immigration into the United States, particularly from .
A. A. Europe
B. B. Asia
C. C. Africa
D. D. South America
【单选题】
The largest minority in the United States is the .
A. A. Pacific Islanders
B. B. Blacks
C. C. Native Americans
D. D. Asians
【单选题】
The native Alaskan population includes the following except the .
A. A. Indians
B. B. Eskimos
C. C. Aleuts
D. D. Blacks
【单选题】
is located on the U. S. –Canadian border between Lake Erie and Lake Ontario.
A. A. Yellowstone National Park
B. B. The Grand Canyon
C. C. Niagara Falls
D. D. The Great Salt Lake
【单选题】
Some of the world famous universities like Harvard, Yale and MIT are located .
A. A. in the South
B. B. along the Pacific Coast
C. C. in New England
D. D. in the Midwest
【单选题】
The largest river in the U. S. is .
A. A. the Missouri River
B. B. the Mississippi River
C. C. the Ohio River
D. D. the Colorado River
