题目内容

For a fluorescent lamp with a rated voltage of 220V, the starting voltage (the minimum voltage required to light the fluorescent lamp) and the extinguishing voltage (the highest voltage required to extinguish the fluorescent lamp) are generally around ( ).

A. 200V and 200V
B. 200V and 100V
C. 100V and 200V
D. 100V and 100V

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Many ships have two types of emergency lighting systems: emergency power system and temporary emergency power system. In terms of power distribution, emergency power system ( ).

A. is a part of normal lighting system
B. can only be powered by an emergency generator
C. no power distribution switch for branch line
D. no control switch for lighting equipment

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In order to ensure the maximum continuous power supply of the marine electrical power system, the operating value setting principle of the short-circuit protection appliances at all levels of the power grid is: step by step towards the generator, the so-called "( )" principle.

A. automatic unloading device
B. inverse time limit
C. sensitivity
D. selectivity

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( ) adjusts the exciting current only according to load current; ( ) adjusts the exciting current only according to the load current pahse.

A. compound compensation/ phase compensation
B. compound compensation/phase compound compensation
C. phase compensation/compound compensation
D. phase compound compensation/phase compensation

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In general, for the automatic frequency adjustment and load control device, cannot realize ( ).

A. let active power sharing even for two generators with different speed characteristic
B. keep network frequency fixed
C. receive disconnecting order,shifting load automatically
D. adjust the number of parallel running generators according to load

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For a fluorescent lamp with a rated voltage of 220V, the starting voltage (the minimum voltage required to light the fluorescent lamp) and the extinguishing voltage (the highest voltage required to extinguish the fluorescent lamp) are generally around ( ).

A. 200V and 200V B. 200V and 100V C. 100V and 200V D. 100V and 100V

Many ships have two types of emergency lighting systems: emergency power system and temporary emergency power system. In terms of power distribution, emergency power system ( ).

In order to ensure the maximum continuous power supply of the marine electrical power system, the operating value setting principle of the short-circuit protection appliances at all levels of the power grid is: step by step towards the generator, the so-called "( )" principle.

( ) adjusts the exciting current only according to load current; ( ) adjusts the exciting current only according to the load current pahse.

In general, for the automatic frequency adjustment and load control device, cannot realize ( ).

A. 200V and 200V
B. 200V and 100V
C. 100V and 200V
D. 100V and 100V