Description : The part of the shipboard electrical system used to control the distribution of power to the branch circuits, is the _____________. A. bridge control panel B. disconnect links C. governor relay box D. main switchboard
Last Answer : Answer: D
Description : What types of modulation are shipboard receive-only equipment designed to receive?
Last Answer : Fm or psk.
Description : What is the function of shipboard receive-only equipment?
Last Answer : To receive fleet multichannel tty broadcasts
Description : When shipboard electrical distribution circuits are connected in parallel, additional parallel circuits will cause the total circuit resistance to _____________. A. increase, causing a drop in the line current B ... an increase in the line voltage D. decrease, causing an increase in the line current
Description : An operating characteristic appearing on the name plates of shipboard AC motors is _____________. A. the type of winding B. input kilowatts C. temperature rise D. locked rotor torque
Last Answer : Answer: C
Description : Which of the following represents a characteristic of an ungrounded electrical distribution system? A. Accidental contact between one line and ground does not cause an outage. B. Double ground faults on ... unnecessary. D. Accidental contact between one line and ground will always cause an outage.
Last Answer : Answer: A
Description : In general AC distribution systems, arc interruption in vacuum circuit breakers are designed to function in a time period of (a) One cycle (b) Two to three cycles (c) Within ten cycles (d) None of the above
Last Answer : In general AC distribution systems, arc interruption in vacuum circuit breakers are designed to function in a time period of One cycle
Description : If the illustrated motor fails to start and gives a loud hum when the start button is pushed, the problem is ________. EL-0007 A. one of the phases to the motor is not energized because of ... electrical distribution system D. 'OL1' is open because of 'T1' overload causing the motor to single phase
Description : The shipboard general alarm system must receive its main source of power from _____________. A. a storage battery B. the emergency generator C. an auxiliary generator D. the ship's service generator
Description : 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
Description : Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one ... The three phases always provide power to the load through three sets of slip rings and brushes.
Description : When paralleled, AC generators must have the same _________. A. frequency B. number of phases C. phase rotation D. all of the above
Description : In the illustration, the component labeled 'G' _________. EL-0031 A. is lined with cardboard to maintain a moisture (electrolyte) barrier between cells B. is a one piece container with compartments for each individual cell C. must be UL approved for shipboard use D. can only contain one cell
Last Answer : Answer: B
Description : Low voltage releases as used in some shipboard motor starter and control equipment will have which of the following characteristics? A. They trip circuit contactors when the motor starts to overspeed. B. ... coil of the starter. D. They allow the motor to restart upon restoration of normal voltage.
Description : When acetone is added in a two layer mixture of methyl isobutyl ketone and water at 30°C, the acetone distributes between the two layers and the composition of the layer follows two solubility curves. For this system ... at the concentration of the plait point (D) All (A), (B) and (C
Last Answer : (D) All (A), (B) and (C
Description : Which of the spaces listed is defined as a 'location requiring an exceptional degree of protection' when considering the installation of shipboard electrical equipment? A. Machinery space B. Chart room C. Console room D. Accommodation space
Description : If the energy input is significantly reduced to the prime mover of one shipboard alternator operating in parallel with others, that alternator will _____________. A. continue to operate at no load B. lose ... overspeed C. begin to motorize and then trip out D. slow down and operate at reduced load
Description : What common shipboard system does figure 'A' represent? EL-0092 A. Navigational running lights B. Rudder angle indicator C. Sound powered telephone D. Winch speed control
Description : The cross-sectional area of shipboard electrical cable is expressed in _____________. A. millimeters B. gage numbers C. centimeters D. circular mils
Description : In shipboard satellite dish antennas system, azimuth is referred as the _______. A. 0 to 90 degrees B. Vertical aiming of the antenna C. North to East D. Horizontal aiming of the antenna
Last Answer : D. Horizontal aiming of the antenna
Description : Which of the following procedures should be used to determine the load of a threephase, delta wound, AC generator? A. Multiply the amperage in one phase by three. B. Divide the total amperage in all ... square root of three. D. Divide the total amperage in all phases by the square root of three.
Description : . If the power distribution system shown in figure 2-22 uses selective tripping, what is the time delay rating for each of the circuit breakers shown?
Last Answer : CB1-long time delay; CB2, CB3-short time delay; CB4 through
Description : What leads in a simple synchro system are connected to the ac power line?
Last Answer : The rotor leads.
Description : What is the reactive power in an ac circuit?
Last Answer : Reactive power is the power returned to the source by the reactive components of the circuit.
Description : What is the true power in an ac circuit?
Last Answer : True power is the power dissipated in the resistance of the circuit or the power actually used in the circuit.
Description : Ships’ generators produce 450-volt, three-phase, ac power; however, most equipment uses 117-volt, single-phase power What transformers and connections are used to convert 450- volt, threephase power to 117-volt, single-phase power?
Last Answer : A method of generating oscillations, a method of turning the oscillations on and off (keying), and an antenna to radiate the energy.
Description : LEDs operating at 850 nm provide sufficient optical power for short-distance, low-bandwidth multimode systems. List three conditions that prevent the use of LEDs in longer distance, higher bandwidth multimode systems.
Last Answer : Multimode fiber dispersion, the relatively high fiber attenuation, and the LED's relatively low optical output power.
Description : What type of synchro is used in systems requiring large amounts of power and a high degree of accuracy?
Last Answer : A control synchro.
Description : Which performance parameter is the minimum amount of optical power required to achieve a specific bit-error rate (BER) in digital systems or a given signal-to-noise ratio (SNR) in analog systems?
Last Answer : Receiver sensitivity.
Description : Compare the power sources of synchros and step transmission systems.
Last Answer : Synchros use ac; step transmission uses dc.
Description : Which of the following is/are true concerning electric power operated watertight door systems? A. Each motor driven door must use the main bus as its source of power. B. Each distribution panel for ... to permit quick activation of the system. D. Each system must have a separate branch circuit.
Description : Federal Regulations (46 CFR) require the circuit in the illustration to _________. EL-0009 A. be at the vessel's ship's service generator distribution switchboard for normal power, normal lighting ... ground will interfere with the operation of electronic equipment D. All the above are correct
Description : Capacitors can be used in electric distribution systems to improve power factor. This is accomplished by seesawing energy between the capacitor and the _____________. A. generator B. inductive loads C. resistive loads D. all of the above
Description : Explain reactive power compensation in Transmission and Distribution systems.
Last Answer : Reactive power compensation in Transmission and Distribution systems: The reactive power is present in lines due to the reactive loads and device/ component reactances. This leads to heavy ... Diagram shows a scheme of reactive power compensation used in transmission and distribution systems.
Description : When using multiple SAW arc systems (twin wires etc), the arcs often have different polarities or use all AC rather than DC polarity, this is to? a) Prevent arc blow between arcs b) To maximize productivity c) To even out the power factor on the mains supply d) Make it easier to initiate the arc
Last Answer : a) Prevent arc blow between arcs
Description : Ammeters and voltmeters used in sinusoidal AC power systems indicate which of the following values of the waveforms measured? A. Peak value B. Root-mean-square value C. Average value D. Maximum value
Description : With regard to the physics of power systems used operate robots, which statement or statements are most correct? a) hydraulics involves the compression of liquids b) hydraulics involves the compression of air c) pneumatics involve the compression of air d) chemical batteries produce AC power
Last Answer : c) pneumatics involve the compression of air
Description : With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power
Last Answer : C : pneumatic involves the compression of air
Description : optical launch conditions exists if the launch spot size and angular distribution are larger than that of the fiber core?
Last Answer : Overfilled.
Description : List three meter movements that can measure either ac or dc without the use of a rectifier.
Last Answer : Electrodynamic, moving vane, and hot-wire or thermocouple.
Description : How can a d’Arsonval meter movement be adapted for use as an ac meter?
Last Answer : By the use of a rectifier
Description : If an ac voltmeter is connected between the S2 and S3 windings on a TX, at what two rotor positions should the voltmeter read maximum voltage?
Last Answer : . 150º and 330º
Description : When used for ac current control, during which alternation of the ac cycle does the TRIAC control current flow?
Last Answer : During both alternations.
Description : What is the basic difference between the primaries of ac and dc rate generators?
Last Answer : The method of primary excitation (ac and permanent magnet).
Description : In the output of an ac error detector, what indicates the (a) direction and (b) amount of control necessary for correspondence?
Last Answer : (a) Phase. (b) Amplitude.
Description : What are the electrons called that give up energy to the ac field in a magnetron?
Last Answer : Working electrons.
Description : Why does using ac vice dc bias voltage result in a stronger output signal?
Last Answer : Because an ac bias voltage of the proper frequency and level places the input signal away from both steps in the magnetism curve. The result is two undistorted output signals that are combined into one strong output.