Term
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Definition
| flow of electric charges per unit time or “flow rate”, measured in “amperes” or “amps” (A). |
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Term
| What is electromotive force? |
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Definition
| a potential difference or “electric pressure” which drives the flow of charges, measured in “volts” (V). |
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Term
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Definition
| an electrical circuit’s opposition to current flow, measured in “ohms” (). |
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Term
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Definition
| a material which offers little resistance to current flow, e.g. silver, copper, iron, etc… |
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Term
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Definition
| a material which offers high resistance to current flow, e.g. wood, paper, plastic, etc... |
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Term
| Which Current flow is unidirectional and of constant magnitude |
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Definition
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Term
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Definition
| current in a circuit is directly proportional to the applied voltage and inversely proportional to the circuit resistance....E=IR |
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Term
| In a circuit which way to electrons flow? |
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Definition
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Term
| What does Kirchoff’s Voltage Law say? |
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Definition
| Sum of all voltages in a complete ckt is zero |
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Term
| What does Kirchoff’s Current Law say? |
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Definition
| Sum of current into and out of a node is always zero and constant. |
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Term
| What is constant in a series circuit? |
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Definition
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Term
| What is constant in a parallel circuit? |
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Definition
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Term
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Definition
| A machine used to convert mechanical energy into electrical energy. |
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Term
| What does Faraday's Law say? |
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Definition
Three things must be present in order to produce electrical current:
1. Magnetic field,
2. Conductor,
3. Relative motion between 1 and 2. |
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Term
| What is the Prime mover in a DC generator? |
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Definition
| mechanical work which turns the rotor, may be a steam turbine, gas turbine, diesel engine... |
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Term
| What is the armature windings in a DC generator? |
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Definition
| the conductor in which the output voltage is induced. |
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Term
| What are the field windings in a DC generator? |
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Definition
| the conductors used to produce the electromagnetic field (needs a DC power supply). |
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Term
| What is the Stator in a DC generator? |
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Definition
| stationary housing of the generator. |
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Term
| What is the rotor in a DC generator? |
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Definition
| rotates inside the stator, moved by a prime mover (steam turbine, gas turbine, diesel…). |
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Term
| What do the sliding contacts (slip-rings and brushes) do in a DC generator? |
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Definition
| used to conduct the field or armature current to and from the rotor. |
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Term
| What does the commutator do in a DC generator? |
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Definition
| Maintains output current in one direction (DC generators). |
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Term
| How can a DC generator be made to act as a DC motor? |
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Definition
| by applying a suitable voltage across its output terminals |
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Term
| How can a DC generator be made to act as a DC motor? |
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Definition
| by applying a suitable voltage across its output terminals |
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Term
| What are the Two Types of AC Generators? |
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Definition
| Revolving armature and revolving field. |
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Term
| What is the prime mover in an AC generator? |
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Definition
| mechanical work which turns the rotor, may be a steam turbine, gas turbine, diesel engine... |
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Term
| What are the armature windings in an AC generator? |
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Definition
| the conductor in which the output voltage is induced. |
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Term
| What are the field windings in an AC generator? |
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Definition
| the conductors used to produce the electromagnetic field (needs a DC power supply), the magnet. |
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Term
| What is the stator in an AC generator? |
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Definition
| stationary housing of the generator, contains the magnet (field windings). |
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Term
| What is the stator in an AC generator? |
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Definition
| stationary housing of the generator, contains the magnet (field windings). |
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Term
| What is the rotor in an AC generator? |
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Definition
| rotates inside the stator, moved by a prime mover (steam turbine, gas turbine, diesel…), contains the conductor (armature windings). |
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Term
| What are the Poles in an AC generator? |
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Definition
| one set of armature windings is called a pole in the generator. |
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Term
| What is the relationship between generator speed and frequency? |
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Definition
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Term
| Most electrical equipment in the United States operates on how many hertz? |
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Definition
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Term
| What frequency does most shipboard power operate on ? |
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Definition
| 60 Hz, some electronic equipment operate at 400 Hz or higher. |
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Term
| What power rating are most shipboard generators? |
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Definition
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Term
| Most shipboard electrical power uses how many phases? |
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Definition
| 3 phases, this is more reliable plus loss of one phase will not cause a loss of equipment operability. |
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Term
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Definition
| A device that transfers energy by electromagnetic induction, it is used to raise voltage (“step-up transformer”) or lower voltage (“step-down transformer”). |
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Term
| How does a transformer raise and lower voltage? |
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Definition
| Voltage is raised when the primary winding has fewer turns than the secondary winding, and voltage is lowered when the primary winding has more turns than the secondary winding. |
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Term
| What does a rectifier do? |
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Definition
| Uses diodes to convert alternating current into direct current. |
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Term
| What amount of current will result in tingles, severe shock, and death? |
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Definition
0.001 amps = 1 milliamp Tingles;
0.01 amps = 10 milliamps Severe; shock , uncontrolled muscle spasms;
0.1 amps = 100 milliamps DEATH! |
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Term
| Which type of power is easier to generate and requires less complex equipment? AC or DC? |
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Definition
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Term
| Which type of power (AC or DC) can be used in transformers to step up or step down voltages ? |
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Definition
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Term
| Which type of power can be can be “stored” for reserve use? |
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Definition
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Term
| What are generators powered by? |
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Definition
| gas turbine, diesel or steam. |
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Term
| What type of generators does the US Navy typically use? |
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Definition
| 450 Volt, 3 phase, 60 Hz; Power approximately 750 - 3000 kW |
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Term
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Definition
| It contains bus-work and distributes electrical power from generator to various circuits. |
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Term
| What is a circuit breaker? |
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Definition
| An electrical device that opens due to various trip set points (over-current, under-voltage, under-frequency) to protect generators and loads. |
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Term
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Definition
| A device that protects the circuit/equipment from possible damage due to excessive current. |
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Term
| What is Selective Tripping? |
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Definition
| A sequence of dropping faulted loads (equipment that has shorted or failed) to prevent widespread electrical outages. |
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Term
| What is Automatic Bus Transfer? |
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Definition
| A device that senses a loss of power from a normal (N) source and will automatically disconnect the load from the normal source and connect it to an alternate (A) source. |
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Term
| What is a Manual Bus Transfer? |
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Definition
| Can connect a load to either a normal (N) or alternate (A) source, but unlike ABT’s (which shift automatically) must be shifted manually. |
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Term
| Name some Uses for Compressed Air. |
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Definition
Automatic combustion controls,
"Prairie" and "masker" systems(masking hull),
Torpedo ejection,
Diesel starting air,
Gas turbine starting air,
Deballasting,
Pneumatic tools,
Weapons system requirements |
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Term
| what are the 5 ways you classify an air compressor? |
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Definition
| Displacement type, Type of staging (# of compressive steps), Type of drive, Operating pressures, Output capacity. |
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Term
| What does Boyle's law say? |
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Definition
| pressure times volume is constant |
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Term
| What does Charle's Law say? |
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Definition
| Volume diveded by Temperature is constant. |
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Term
| What does the Ideal gas law say? |
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Definition
| Pressure times volume diveded by temperature is equal to nR????? |
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Term
| Why do we use multiple stage air compressors? |
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Definition
| Smaller and lighter and Lower operating temperatures. |
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Term
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Definition
| Removes moisture not removed by inter- and after-coolers |
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Term
| List 5 uses for compressed air. |
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Definition
| 1-ACC, 2-prarie and masker systems, 3-torpedo ejection, 4- Diesel starting air, 5- Gas turbine starting air. |
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Term
| What does the navy do to protect against the diesel effect? |
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Definition
| Has filters and dehydrators and reducers to protect against the diesel effect. |
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Term
| What are some concerns for a High Pressure Air Rupture? |
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Definition
Severe damage of equipment personnel,
Difficult to locate,
Very loud noise – sometime confused with flooding,
Increase of compartment pressure possible. |
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Term
| What are the Requirements for Motor Action? |
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Definition
1) Conductor
2) Magnetic Field
3) Current
-OR-
Current-carrying conductor in a magnetic field |
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Term
| what are the Requirements for Generator Action? |
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Definition
1) Conductor
2) Magnetic Field
3) Relative Motion Between the Conductor and Magnetic Field
Remember a generator does not require current because that is what it produces |
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Term
| What are the Requirements for Paralleling AC Generators? |
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Definition
1) “In phase” (the 2 generators electrical outputs must be in phase)
2) “Voltage” (the 2 generators’ output voltages must be matched)
3) “Frequency” (the oncoming generator’s output frequency must be higher than the running generator’s output frequency)
4) “Proper Phase Sequence” (Both generators’ outputs must be in the proper phase sequence) |
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Term
| What are the Freshwater Production Methods? |
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Definition
| Distilling and Desalinating. |
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Term
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Definition
| High pressure salt “filtration”. |
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Term
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Definition
| Boiling seawater and condensing vapor |
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Term
| name the Types of Distilling Plants. |
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Definition
Flash Type Distilling,
Vertical Basket Distilling,
Vapor Compression Distilling. |
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