competence 6

46問 • 1年前

問題一覧

Depending upon the design of boiler, the constant pressure mainteained at the steam drum or the superheat outlet is known as ?

operating pressure

What utilizes a pure transducer utilizes?

proportion action

The total heating surface of any steam generating unit is comprised of ?

Those parts of boiler which are exposed on one side to only water or steam being heated, and on the other side of the combustion gases.

What methods are used to control the time that current is limited before full current is applied?

Wye-delta starter

What is a kind of temperature detecting element formed by a pair of dissimilar metals joined at one end and elsewhere isolated electrically from each other which produces a small electrical signal ?

Thermocouple

What is the description in the source voltage in a prallel circuit?

is inversely proportional to each branch current

How can you determine if a circuit breaker is tripped?

Examining the postion of the handle

The type of feature afforded to auxiliaries vital to the operation of propelling equipment, where automatic restart after a voltage failure would not create a hazard, which of the following termed is used to describe the process ?

low voltage release

Which of the following is required onboard, to perform before any work on a high voltage equipment commences to ensure that any stored electrical energy in the inherent capcitance of the equipment insulation is safely discharge after isolation ?

Earthing

What do you call a directional lighting to emphasize an object or draw atention to a part of the field view

accept lighting

Which of the following statements is true concerning a polyphase synchronous propulsion motor?

The motor is started as an incution motor,

To be considered as High Voltage system used on board a ship, how much should be the minimum voltage?

1000V

In a simple DC circuit, the resistance is held constant when the applied voltage is halved. Current flows therefore will

be divided by two

Which of the following statement will affect the capacity value of a capacitor?

the flow of current in the circuit

Which prevents the entry of large objects to the pipeline and safeguards the internal parts of the pumps ?

Mud box

What is the part of a transformer which function is to deliver the load received ?

secondary winding

Re-circulating of the feed water ensures a flow of water through?

Main feed pump

Which of the listed actions should be taken first if one trips out mechanically in two paralleled alternators that are operating near rated load?

Strip the board of all nonvital circuits.

The dielectric strength of transformer oil is expected to be

33kV

The capacitance is measured in

farads

A low-voltage protection circuit is used in electric motor starting equipment to

prevent the motor from restarting automatically on restoration of voltage

The spped of a series wound winch motor is controlled by:

varying the voltage applied to the motor

The type of permanent magnets are normaly made of ?

alnico alloy

The speed of a squirrel-cage, multi-speed induction motor, as used aboarship, is best varried by changing the

Numver of connected poles in the stator

Determine the main difference of marine high voltage installation compared to low voltage installation onboardship.

High voltage systems are usually earthed neutral and use current limiting resistors

When trouble shooting an electronic circuit, a cold solder joint can be located with the aid of an ohmmeter. Once the problem has been located , what should you do next?

reheat connection with a soldering tool and recheck with an ohmmeter

The ground indicating light on the main electrical switchboard is indicating a ground. The best procedure for locating grounded circuit is to

Open the circuit breakers on the distribution panel, one at a time until the light no longer indicate a ground

For a galley equipment the molded case breaker that provide protection against short circuits uses a/an?

electromagnet

Which one of the following best describes the meaning of the term attracking a when applied to high voltage electrical systems?

it is a current that flows within insulation layers

What is the direction of the magnetic field in a conductor when current is flowing?

in a direction determined by the left hand rule

Prior to starting an AC generator prime mover, the voltage regulator cut out switch should be placed to what position?

manual

When paralleling two alternators, the synchronizing lamps remain lit as the synchroscope pointer approaches the O° position. This indicates the ?

synchroscope is defective or broken

Which one of teh following is best described as the combination of electrical disconnect switches and circuit breakers that are used to control, protect and isolate high-voltage electrical equipment?

Switchgear

Prior to starting an AC generator prime mover, the voltage regulator cut out switch should be placed in which of the following position?

Position to manual

Why is it necessary to measure bolted bus bar joint resistance?

Because as high current flows through the bus bar, any resistance in it causes resistive heating

What might be the cause if an electric motor of an electric driven compressor fails to start?

Tripped circuit breaker

Which of the following is not provided in a switchboard for an AC electrical distribution system?

transducer

The purpose of checking the electrical installation, equipments, etc. using a megger tester?

Load to carry

Which of the following high-voltage testing tools are necessary to test the arc suppression medium in contact cylinders of high-voltage circuit breakers and high-voltage cotactors?

Integrity testers

In process control terminology values which can change without distinct increments, such as temperature, pressure or level are called

analog values

Ina cross-compound main propulsion unit, the astern turbine is usually INSTALLED WHERE?

Low pressuer end of the low pressure turbine

When trouble shooting electronic equipment, the first step to be taken before testing the circuit voltage is to

check the votlage supply from the power source

Identify factor that determines the frequency of an alternator?

number of magnetic poles

What is known as a conduction carrier opposite to the majority current carrier which are represented by the holes in N-type material and free electrons in a P-type material?

Minority Current Carrier

Pt100 is a type of resistance temperature dependent sensor, mostly applied if very accurate temperature reading is required,. What does Pt100 mean?

Platinum element with a resistance of 100 ohm 2 0 degc

Which of the following statements represents an application of a silicon controlled rectifier ?

Not synchronized, current is flowing and the relays are closed

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