Electricity - Basic Navy Training Courses

Here is the "Electricity - Basic Navy Training Courses" (NAVPERS 10622) in its entirety. It should provide one of the Internet's best resources for people seeking a basic electricity course - complete with examples worked out. See copyright. See Table of Contents.





  • AGONIC: An imaginary line of the earth's surface passing through points where the magnetic declination is 0°, that is, points where the compass points true north.
  • ALTERNATOR: An alternating current generator. AMMETER: The instrument for the measurement of current.
  • AMPERE: The unit of electrical current.
  • AMPERE-HOUR: The quantity of electricity equivalent to a current of one ampere flowing past a point in a conductor in one hour.
  • AMPERE-TURN: The magnetizing force produced by a current of one ampere flowing through a coil of one turn.
  • ANODE: The electrode in a cell (voltaic or electrolytic) that attracts the negative ions and repels the positive; the positive pole.
  • ARC: The luminous glow between incandescent electrodes.
  • ARMATURE: The movable part of a motor or the removable part of a magnetic circuit, such as the iron placed across the poles of a horseshoe magnet.
  • AUTO-TRANSFORMER: A transformer in which the primary and secondary are connected together in one winding.
  • BATTERY: A. group of several cells connected together as a unit.
  • BRANCH CIRCUIT: One of the conductors in a parallel circuit.
  • BRUSH: The conducting material, usually a block of carbon, bearing against the commutator or slip-rings through which the current flows in or out.
  • CATHODE: The electrode in a cell (voltaic or primary) that attracts the positive ions and repels the negative ions; the negative pole.
  • CHOKE COIL: A coil of low ohmic resistance and comparatively high impedance to alternating current.
  • -CIRCUIT: The complete path of an electric current including, usually, the generating device.
  • CIRCUIT BREAKER: A device that opens a circuit while it is carrying current; often used in abnormal conditions, such as overloads.
  • CIRCULAR MIL: An area equal to that of a circle with a diameter of 0.001 inch. It is used for measuring the cross section of wires.
  • COMMUTATOR: That part of the armature of a dynamo which converts an alternating into a direct current.
  • CONDENSER: A device consisting of two or more conductors separated by non-conductor material; it holds or stores an electric charge.
  • CONDUCTANCE: The reciprocal of electrical resistance. Conducting power.
  • CONDUCTIVITY: The ease with which a substance transmits electricity.
  • CONDUCTOR: A material capable of transmitting electric current.
  • CONVERTER, ROTARY: An electrical machine having a commutator at one end and slip-rings at the other end of the armature. It is used for the conversion of alternating to direct current.
  • CORE: A mass of iron placed inside a coil to increase its magnetism.
  • COULOMB: The-unit of static electricity; the quantity of electricity transferred by one ampere in one second.
  • COUNTER EMF: Counter electromotive force; an EMF induced in a coil or armature that opposes the applied voltage.
  • CURRENT OF ELECTRICITY: The continuous flow of electrons in a circuit.
  • D'ARSONVAL GALVANOMETER: A galvanometer in which a moving coil swings between the poles of a permanent horseshoe magnet.
  • DEMAGNETIZE: To deprive a body of its magnetic properties.
  • DIELECTRIC: A non-conducting material.
  • DIODE: A vacuum tube containing the filament and the plate; it serves as a rectifier of alternating current.
  • DIP NEEDLE: A magnetized needle capable of rotation in a vertical plane.
  • DIRECT CURRENT: An electric current that flows in one direction only.
  • DYNAMO: A machine for converting mechanical energy into electrical energy or vice versa.
  • EDDY CURRENT: A current induced in the core of an armature of a motor, dynamo, or transformer caused by changes in the magnetic field.
  • EFFICIENCY: The ratio of a machine's useful work output to the total input.
  • ELECTRODE: The terminal by which current leaves or enters an electrolytic cell.
  • ELECTROLYTE: A substance that conducts a current by the movement of ions.
  • ELECTROMAGNET: A magnet made by passing current through a coil of wire wound on a soft iron core.
  • ELECTROMOTIVE FORCE (EMF): The electrical force that moves or tends to move electrons; ELECTRON: The smallest particle of negative electricity.
  • ELECTROPLATING: The electrical method of plating a surface with a metal.
  • ENERGY: The ability or capacity to do work.
  • FIELD: The region where a magnet or electrical charge is capable of exerting its force.
  • FIELD COIL: One of the coils used to excite a field magnet.
  • FIELD MAGNET: The magnet used to produce a magnetic field (usually in motors or generators).
  • FLUX: Magnetic lines of force, assumed to flow from the north pole to the south pole of a magnet.
  • FREQUENCY: The number of cycles of an alternating current per second.
  • FUSE: A part of a circuit made of a material that will melt and break the circuit when current is increased beyond a specific value.
  • GALVANOMETER: An instrument used to measure small currents.
  • GENERATOR: A machine that converts mechanical energy into electrical energy.
  • GRID: A metal wire mesh placed between the cathode and plate.
  • GRID BATTERY: The battery used to supply the desired potential to the grid.
  • GRID LEAK: A very high resistance placed in parallel with the grid condenser.
  • GROUND: A connection made directly to the earth or to a frame or structure which serves as one line of a circuit.
  • HORSEPOWER: The English unit of power, equal to work done at the rate of 550 foot-pounds per second. Equal to 746 watts of electrical power.
  • INDUCE: To produce an effect in a body by exposing it to the influence-of a magnetic force, an electric force, or a changing current.
  • INDUCTION COIL: Two coils so arranged that an interrupted current in the first produces a voltage in the second.
  • INTERRUPTER: A device for the automatic making and breaking of an electrical circuit.
  • ION: An electrically charged atom.
  • ISOGONIC LINE: An imaginary line drawn through points on the earth's surface where the magnetic deviation is equal.
  • JOULE: A unit of energy or work. A joule of energy is liberated by one ampere flowing for one second through a resistance of one ohm.
  • LAG: The number of degrees an alternating current lags behind voltage.
  • LAMINATIONS: The thin sheets or discs making up an iron core.
  • LEYDEN JAR: An early form of condenser.
  • LINE OF FORCE: A line in a field of force that shows the direction of the force.
  • LOAD: The energy delivered by a generator to its circuit.
  • LODESTONE: A piece of magnetite.
  • MAGNETIC CIRCUIT: The complete path followed by magnetic lines of force.
  • MAGNETIC FLUX: The total number of lines of force issuing from a pole.
  • MAGNETITE: An iron ore that is magnetic.
  • MAGNETO: A generator in which the field is sup- plied by a permanent magnet.
  • MEGOHM: A million ohms.
  • MIL: One thousandth of an inch.
  • MILLIAMMETER: An ammeter reading thousandths of an ampere.
  • MILLIVOLTMETER: A voltmeter reading thousandths of a volt.
  • MOTOR-GENERATOR (M-G): A generator driven by an electric motor.
  • MUTUAL INDUCTION: The inducing of an EMF in a circuit by the field of a nearby circuit.
  • NEGATIVE CHARGE: The electrical charge carried by a body which has an excess of electrons. (For example, a vulcanic rod, after it has been rubbed by fur or wool, carries a negative charge.)
  • NEUTRON: A particle having the weight of a pro-ton but carrying no electric charge.
  • NUCLEUS: The heavy or central part of an atom. OHMMETER: An instrument for directly measuring ohms.
  • PERMALLOY: An alloy containing 78.5 percent nickel and 21.5 percent iron. It has an abnormally high magnetic permeability.
  • PERMEABILITY: A property of matter that indicates the ease with which it is magnetized.
  • PLATE CURRENT: The current that flows from the plate of a vacuum tube.
  • POLARITY: The character of having magnetic poles, or electric charges.
  • POLE: One of the ends of a magnet where most of its magnetism is concentrated.
  • POSITIVE CHARGE: The electrical charge carried by a body which has become deficient in electrons. (For example, a glass rod, after it has been rubbed by silk, carries a positive charge.)
  • POTENTIAL: The amount of charge held by a body.
  • POWER: The time rate of doing work.
  • PROTON: A positively charged, particle whose charge is equal, but opposite, to that of the electron.
  • RECTIFY: To change an alternating current to a unidirectional or direct current.
  • RELAY: An electrically operated device for the closing and opening of a circuit.
  • RELUCTANCE: A measure of the resistance of a material to magnetic lines of force.
  • RESISTANCE: The opposition of a conductor to an electric current.
  • RETENTIVITY: The property of retaining magnetism.
  • SATURATION, MAGNETIC: The condition of a magnetic substance when its magnetism has reached its highest possible value.
  • SELF INDUCTION: The process by which a circuit induces an EMF in itself by its own magnetic field.
  • SERIES CONNECTION: An arrangement of cells, generators, condensers, or conductor each carries the entire current of the circuit.
  • SERIES-WOUND: Having the armature wired in series with the field winding. (Applied to motors or generators.)
  • SOLENOID: A coil of wire used to produce a magnetic field.
  • SPACE CHARGE: The charge acquired by the space inside a vacuum tube due to the presence of electrons.
  • STEP-DOWN TRANSFORMER: A transformer with fewer turns in the secondary than in the primary.
  • STEP-UP TRANSFORMER: A transformer with more turns in the secondary than in the primary.
  • THERMOCOUPLE: A pair of metals which generate an EMF by the heating of one of the junctions; it is used to measure temperature differences.
  • TRANSFORMER: A device that, without moving parts, transfers electrical energy from one circuit to another circuit by the aid of electromagnetic induction.
  • TRIODE: A vacuum tube containing a filament, grid, and plate.
  • UNIDIRECTIONAL: As applied to a current of electricity, a current that flows in one direction only.
  • VACUUM TUBE: A tube from which the air has been pumped out. The tube contains an element that emits electrons when properly excited and an electrode to attract the electrons and set up a current in an external circuit.
  • VOLT: The practical unit of electrical pressure.
  • WATT: A unit of power produced by a current of one ampere at one volt.
  • WATTMETER: An instrument for measuring electric power in watts.





   For voltage ............... E = IR
   For current ............... I = E/R
   For resistance .......... R = E/I
   For power ................ P = IE
                                     P = I2R
                                     P = E2/R
   For current ............... I = P/E
   For voltage .............. E = P/I
   For current .............. I = (Ea - Eg)/Ra
   For IR drop .............. IR = Ea - Eg
   Voltage-turns .......... Ep/Es = Tp/Ts
   Current-turns .......... Ip/Is = Is/Ip
   Power ...................... IpEp = IsEs
   Ampere-turns .......... IpTp = IsTs
   For voltage ............... Et = E1 + E2 + E3 ...
   For current ............... It = I1 = I2 = I3 ...
   For resistance .......... Rt = R1 + R2 + R3 ...
   For voltage .............. Et = E1 = E2 = E3 ...
   For current .............. It = I1 + I2 + I3 ...
   For resistance ......... 1/Rt = 1/R1 + 1/R2 + 1/R3 ...
   For hp ...................... hp = P/746
   For watts ................. P = 746 hp