网友您好, 请在下方输入框内输入要搜索的题目:
题目内容
(请给出正确答案)
单选题
When paralleling two AC generators, the frequency of the machine coming on-line, immediately prior to closing its breaker, should be ()
A
slightly less than the oncoming generator frequency
B
the same as the bus frequency
C
slightly greater than the bus frequency
D
the same as the bus voltage
参考答案
参考解析
解析:
暂无解析
更多 “单选题When paralleling two AC generators, the frequency of the machine coming on-line, immediately prior to closing its breaker, should be ()A slightly less than the oncoming generator frequencyB the same as the bus frequencyC slightly greater than the bus frequencyD the same as the bus voltage” 相关考题
考题
单选题Which condition indicates the air side fouling of an after-cooler on a turbocharged diesel engine?()A
An increased air temperature differential between the cooler inlet and outletB
A decrease in the air pressure differential across the coolerC
Excessive condensate forming in the air boxD
A decrease in the air temperature differential between the cooler inlet and outlet
考题
单选题大型柴油机在拆卸主轴承下瓦时,正确的做法是()。A
按发火顺序依次拆卸轴承B
每次只允许拆卸一道轴承,待装入后再拆第二道轴承C
同时可以拆卸几道轴承,每道轴承必须做好记号D
先从自由端开始至飞轮端依次拆卸轴承
考题
单选题Which of the following statements describes one of the functions of the ballast system?()A
To permit flooding of any fuel oil storage tank on any class of shipB
To use it as a secondary service systemC
To store reserve feed or potable water for extended cruisesD
To stabilize the ship by flooding certain designed tanks with seawater
考题
单选题按照我国《钢质海船入级规范》规定,当船舶交流电网的电压、频率发生波动,其稳态值分别在()范围内,交流电器设备能有效地工作。A
±10%Un、±5%fnB
±5%Un、±10%fnC
-6%~+10%Un、±5%fnD
-10%~+15%Un、±5%fn
考题
单选题Moisture absorbed in the windings or condensed on the surface of electrical machinery insulation ()A
is good for long term preserving since most insulation is organic and contains some amountB
lowers the insulation value and is a common cause of fault grounds in idle machinesC
will enhance insulation resistance only if it is fresh water and contains no saltD
reduces the amount of current supplied or drawn by the machine so horsepower is limited
考题
单选题When entering a foam injected space () breathing apparatus.A
put outB
put onC
take offD
take in
考题
单选题Which statement about satellite navigation is TRUE? ()A
While a fix can be generated by signals received from two satellites,three satellites are necessary for reliable accuracyB
The satellites are in equatorial orbits around the earth about 60°of longitude apartC
The satellite navigation system determines a fix by measuring the doppler shift of the radio signals from the satelliteD
The ship's receiver cannot begin processing data until the antenna locks onto the satellite and starts continuous tracking
考题
单选题海图图廓注记通常包括下列哪些内容()。 Ⅰ.图名;Ⅱ.图号;Ⅲ.图幅;Ⅳ.小改正;Ⅴ.出版和发行情况;Ⅵ.重要注意和警告;Ⅶ.坐标系说明。A
Ⅰ~ⅣB
Ⅱ~ⅤC
Ⅲ~ⅥD
Ⅳ~Ⅶ
考题
单选题Which of the following conditions would cause carbon deposits to form in the piston ring belt of a diesel engine?()A
faulty combustionB
excessive ring temperatureC
over lubricationD
all of the above
考题
单选题An alarm device inserted between the deaerating tank and the expansion tank can notify the on-watching crew that ()A
the expansion tank is lack of waterB
the expansion tank is over flowingC
there is something wrong with the cooling systemD
there is something wrong with the engine
考题
单选题根据ISPS规则的有关演习和演练的规定,以下正确的是()。 Ⅰ、为确保有效实施船舶保安计划的规定,应至少每三个月进行一次演练 Ⅱ、如25%船员变动且在前三个月未参加任何演练,应在变动后1周内进行演练 Ⅲ、可能有CSO、SSO、PFSO等参加的各类演习,至少每年1次A
Ⅰ、Ⅱ对B
Ⅰ、Ⅲ对C
Ⅱ、Ⅲ对D
以上都正确
考题
单选题对于柴油机滑油状态监控系统,润滑油油样分析时,一般应先进行油的理化性能分析和光谱分析,然后在此基础上进行()分析,必要时再作()分析。A
直读式铁谱仪/分析式铁谱仪B
直读式铁谱仪/旋转式铁谱仪C
旋转式铁谱仪/分析式铁谱仪D
分析式铁谱仪/直读式铁谱仪
热门标签
最新试卷