更多"Electrical circuits are protected a"的相关试题:
[单项选择]Electric circuits are protected against overloads and short circuits by means of a/an （）.
A. circuit breaker
B. amplifier
C. diode
D. capacitor
[单项选择]Electric generators can be protected against overload（）.
A. With switches
B. With a governor on the engine
C. With fuses or circuit breakers
D. By using heavy wire
[单项选择]当风挡过热（WINDOW OVERHEAT）灯亮时的最大空速限制为（）
A. 250海里
B. 280海里
C. 低于10000英尺250海里
D. 低于10000英尺280海里
[名词解释]
保护区（Protected area）
[单项选择]左"管道过热（DUCK OVERHEAT）"灯亮时，空气混合活门处于什么位置：（）
A. "全冷"位
B. "全热"位
C. 中间位
D. 保持在灯亮时的位置
[单项选择]右"管道过热（DUCK OVERHEAT）"灯亮，说明系统的哪一部分超温（）
A. 客舱管道
B. 引气管道
C. 组件温度超过限制
D. 右空气循环机
[名词解释]电气设备（electrical equipment）
[单项选择]In motorships，there are two main circuits, （）.
A. one salt water, one fresh water
B. one salt water, one fuel
C. one fresh water, one fuel
D. one steam, one fuel
[单项选择]Which of the following devices are protected from being motorized by a reverse-power relay?（）
A. Alternators
B. Wave guides
C. Exciters
D. Amplidynes
[单项选择]Accidental grounds in a shipboard electrical system must be repaired as soon as possible as they will （）
A. result in immediate power outages
B. damage circuit breakers
C. appear on the ground detection system
D. damage insulation and may cause outages
[单项选择]Electrical power is expressed in （）
A. ohms
B. volts
C. amps
D. watts
[单项选择]Grease coatings on electrical contact surfaces increase contact resistance and should be removed with a/an （）.
A. small wire brush
B. compressed air jet
C. clean dry cloth
D. 10% solution carbon solvent and water
[单项选择]Complete maintenance of electrical motors should include periodic checks for machine （）
A. vibration
B. watertight integrity
C. speed droop
D. reactive power
[单项选择]The greatest detrimental effect on idle electrical equipment, such as cargo pump motors, is the（）.
A. loss of residual magnetism
B. absorption of moisture in the insulation
C. insulation varnish flaking
D. dirt collecting on the windings
[单项选择]Before doing maintenance on electrical equipment, you should （）.
A. turn off power first
B. turn on power first
C. with a test pen in hand
D. tell C/E
[单项选择]How should cargo tank hatches be protected when the ullage opening is open and the tank not gas free?（）.
A. With gooseneck vents
B. With warning signs
C. With flame screens
D. With pressure-vacuum relife valves
