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| what are the kinds of losses of electrical power in a transformer |
copper losses
Eddy losses
hysteresis losses |
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usnavalmd Sat, 10 Jan 2009 18:35:39 GMT |
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| what is the efficiency of a transformer |
the ratio of the power output to the power input |
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usnavalmd Sat, 10 Jan 2009 18:35:39 GMT |
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| what type of transformer is the most advanced type, used as a power or commercial transformer |
shell type |
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usnavalmd Sat, 10 Jan 2009 18:35:39 GMT |
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| what type of transformer consists of heavily insulated coils wound around a square or circular iron ring or core |
closed core |
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usnavalmd Sat, 10 Jan 2009 18:35:39 GMT |
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| what type of transformer consists of an iron core inserted into a coil of wire carrying an eletric current |
open core |
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usnavalmd Sat, 10 Jan 2009 18:30:04 GMT |
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| what type of transformer consists of two types of highly insulated coils lying side by side |
air core |
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usnavalmd Sat, 10 Jan 2009 18:31:53 GMT |
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| what are the four types of transformers |
air core
open core
closed core
shell type |
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usnavalmd Sat, 10 Jan 2009 18:30:04 GMT |
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| what is the formula for the conservation of energy for a transformer |
IsVs = IpVp |
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usnavalmd Sat, 10 Jan 2009 18:30:03 GMT |
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| what is the law of conservation of energy for a transformer |
there can not be more energy put out of a transformer than what is put in |
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usnavalmd Sat, 10 Jan 2009 18:22:44 GMT |
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| what is the formula for transformer law |
Vs/Vp = Ns/Np |
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usnavalmd Sat, 10 Jan 2009 18:22:44 GMT |
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| a transformer that has more turns in the secondary coil than in the primary coil is considered to be what type of transformer |
step up |
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usnavalmd Sat, 10 Jan 2009 18:22:44 GMT |
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| a transformer that has more turns in the primary coil than in the secondary coil is considered to be what type of transformer |
step down |
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usnavalmd Sat, 10 Jan 2009 18:22:44 GMT |
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| what are the two types of coils a transformer has |
1.primary
2.secondary |
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usnavalmd Sat, 10 Jan 2009 18:17:16 GMT |
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| what employs the principle of electromagnetic mutual induction |
transformers |
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usnavalmd Sat, 10 Jan 2009 18:17:16 GMT |
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| an electromagnetic device which changes an alternating current from low voltage to high voltage, high voltage to low voltage, without loss of an appreciable amount of electrical energy |
transformer |
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usnavalmd Sat, 10 Jan 2009 18:17:16 GMT |
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| what are the two types of electric motors |
direct current motors
alternating current motors |
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usnavalmd Sat, 10 Jan 2009 18:17:16 GMT |
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| what type of motor is used to operate the tilt of the xray table and used to turn the anode of the xray tube |
induction motor |
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usnavalmd Sat, 10 Jan 2009 18:10:24 GMT |
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| what type of motor has a strator and a rotor |
induction motor |
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usnavalmd Sat, 10 Jan 2009 18:10:24 GMT |
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| what are the two main types of alternating current motors |
synchronous motor
induction motor |
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usnavalmd Sat, 10 Jan 2009 18:10:53 GMT |
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| what is used to determine the direction of the movement of the conductor in an electric motor |
right hand motor rule |
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usnavalmd Sat, 10 Jan 2009 18:08:27 GMT |
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| what two conditions must prevail in the principle operation of the electric motor |
1.the conductor must carry a current
2.the conductor must be located in a magnetic field |
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usnavalmd Sat, 10 Jan 2009 18:08:27 GMT |
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| a device that converts electrical energy to mechanical energy |
electric motor |
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usnavalmd Sat, 10 Jan 2009 18:08:27 GMT |
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| what are the two advantages of AC over DC |
AC is needed to operate transformers
less power loss in AC than DC |
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usnavalmd Sat, 10 Jan 2009 18:42:34 GMT |
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| what is the fluctuations of current and voltage as shown on the sine wave |
ripple |
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usnavalmd Sat, 10 Jan 2009 15:46:42 GMT |
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| what is the term used to describe the difference in phase relationship between voltage and current |
phase angle |
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usnavalmd Sat, 10 Jan 2009 15:42:51 GMT |
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| In an AC generator if the current and voltage reach zero together, rise and fall together, and attain peak values together are considered to be what |
in phase or in step |
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usnavalmd Sat, 10 Jan 2009 15:39:49 GMT |
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| In an AC generator if the current and voltage are not in step with each other it is considered to be what |
out of phase |
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usnavalmd Sat, 10 Jan 2009 15:39:49 GMT |
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| what is the formula for ohm's law as it refers to an AC circuit |
I=V/Z |
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usnavalmd Sat, 10 Jan 2009 15:39:49 GMT |
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| the unit of measure for impedance is what |
ohm (Z) |
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usnavalmd Sat, 10 Jan 2009 15:39:49 GMT |
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| the total opposition to the current flow in an AC circuit |
Impedance |
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usnavalmd Sat, 10 Jan 2009 18:43:17 GMT |
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| if a capacitor is added to an AC circuit and the polarity reverses as the current reverses the amount of hinderance to the flow of current is known as what |
capacitive reactance |
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usnavalmd Sat, 10 Jan 2009 15:33:09 GMT |
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| in a DC circuit what allows current to flow only until it has reached full charge whereupon the current ceases to flow |
capacitor |
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usnavalmd Sat, 10 Jan 2009 15:33:09 GMT |
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| what is the "bucking" tendency of inductance in an alternating current circuit |
inductive reactance |
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usnavalmd Sat, 10 Jan 2009 15:33:09 GMT |
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| the opposition to a change in the amount of current flowing in an alternating circuit |
inductance |
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usnavalmd Fri, 09 Jan 2009 19:10:21 GMT |
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| the factor which, in an AC circuit, causes the impedance to be larger than resistance |
reactance |
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usnavalmd Fri, 09 Jan 2009 19:10:21 GMT |
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| in a sine curve what is the maximum value of a given alteration measured from zero to peak |
amplitude |
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usnavalmd Fri, 09 Jan 2009 19:10:21 GMT |
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| In a sine curve what is the measure of power from a negative peak to a positive peak |
peak to peak value |
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usnavalmd Fri, 09 Jan 2009 15:51:34 GMT |
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| what is the common use in the US for hertz |
60 Hz |
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usnavalmd Fri, 09 Jan 2009 15:51:33 GMT |
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| what is the unit of measure for frequency |
hertz |
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usnavalmd Fri, 09 Jan 2009 15:51:33 GMT |
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| what is the number of cycles per second called in an alternating current |
frequency |
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usnavalmd Sat, 10 Jan 2009 18:45:02 GMT |
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| what is the curve called that shows the relationship of the alternating current to the succesive positions of the generator armature as it rotates between the magnetic poles |
sine curve |
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usnavalmd Thu, 08 Jan 2009 16:16:57 GMT |
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| what are the components of a simple generator |
field magnet
armature
shaft
collector or slip rings
brushes |
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usnavalmd Thu, 08 Jan 2009 16:16:57 GMT |
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| what is the device that converts mechanical energy to electrical energy by electromagnetic induction |
electrical generator or dynamo |
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usnavalmd Thu, 08 Jan 2009 16:16:57 GMT |
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| the process of inducing a current flow through a secondary coil by passing a varying current through the primary coil |
mutual induction |
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usnavalmd Tue, 06 Jan 2009 14:17:39 GMT |
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| the induction of an opposing EMF in a single coil by its own changing magnetic field |
self induction |
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usnavalmd Tue, 06 Jan 2009 14:17:39 GMT |
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| what are the two types of induction |
self induction
mutual induction |
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usnavalmd Tue, 06 Jan 2009 14:12:21 GMT |
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| what law states the induced current will flow in a direction such that it opposes the action that induces it |
Lenz's Law |
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usnavalmd Tue, 06 Jan 2009 14:12:21 GMT |
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| what rule is used to determine the direction of induced electric current |
left hand or dynamo rule |
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usnavalmd Tue, 06 Jan 2009 14:12:21 GMT |
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| what are the four factors that determines the number of lines of force cut per second |
1. speed with which a conductor cuts magnetic lines of force
2. strength of the magnetic field
3. angle between the conductor & the direction of the magnetic field
4. number of turns in the conductor |
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usnavalmd Tue, 06 Jan 2009 14:12:21 GMT |
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| the magnitude or size of the induced EMF depends on what |
the number of lines of force cut per second or the number of flux linkages per second |
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usnavalmd Tue, 06 Jan 2009 13:56:31 GMT |
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| what are the three ways to induce an EMF or voltage in a wire by electromagnetic induction |
1.the wire may move across a stationary magnetic flux
2.the magnetic flux may move across a stationary wire
3.the magnetic flux may vary in strength while a stationary wire lies in it |
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usnavalmd Tue, 06 Jan 2009 13:56:31 GMT |
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| what is the interaction between a line of force and a single loop conductor |
flux linkage |
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usnavalmd Tue, 06 Jan 2009 13:56:31 GMT |
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| what is the process of inducing an electromotive force into a conductor as it cuts magnetic lines of force |
electromagnetic induction |
1 |
usnavalmd Sat, 10 Jan 2009 18:47:31 GMT |
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| what determines the strength of the magnetic field in an electromagnet |
ampere turns
type of core material |
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usnavalmd Mon, 05 Jan 2009 18:58:24 GMT |
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| what is a solenoid with an iron core called |
electromagnet |
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usnavalmd Mon, 05 Jan 2009 18:52:46 GMT |
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| what can be predicted with the left hand rule |
direction of the magnetic flux inside the coil
which end of the coil will be the north |
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usnavalmd Mon, 05 Jan 2009 18:52:46 GMT |
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| what two factors determines the strength of the magnetic field in a coiled conductor (solenoid) |
amount of the current in the coil
the number of turns in the coil |
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usnavalmd Mon, 05 Jan 2009 18:56:51 GMT |
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| what is a helix or coiled conductor carrying an electric current |
solenoid |
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usnavalmd Mon, 05 Jan 2009 18:52:46 GMT |
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| if the conductor is grasp with the left hand with the thumb pointing in the direction of current flow, then the fingers encircling the wire will indicate what |
the direction of the magnetic lines of force around the current |
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usnavalmd Mon, 05 Jan 2009 18:42:04 GMT |
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| In magnetic effect, the greater the current flow... |
the greater the resulting magnetic field |
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usnavalmd Mon, 05 Jan 2009 18:42:04 GMT |
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true or false:
a magnetic field always surrounds a conductor in which an electric current is flowing |
true |
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usnavalmd Mon, 05 Jan 2009 18:42:04 GMT |
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| what is the branch of physics that deals with the relationship between electricity and magnetism |
electromagnetism |
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usnavalmd Mon, 05 Jan 2009 18:42:04 GMT |
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| what is the unit of measure for the capacitance |
farad |
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usnavalmd Mon, 05 Jan 2009 18:30:57 GMT |
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| what is the quanity of electrical charge, in coulombs, stored per volt, applied to the capacitor called |
capacitance |
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usnavalmd Mon, 05 Jan 2009 18:30:56 GMT |
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| what are the three limits of a parallel plate capacitor |
size of the plates
distance between the plates
types of diaelectric material |
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usnavalmd Mon, 05 Jan 2009 18:30:56 GMT |
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| what is connected to the plates of parallel plate capacitor to deliver and recieve current |
wiring (conductor) |
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usnavalmd Mon, 05 Jan 2009 18:30:56 GMT |
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| what is the insulative material placed between the plates of a parallel plate capacitor |
diaelectric material |
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usnavalmd Mon, 05 Jan 2009 18:22:53 GMT |
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| what is the simplest type of capacitor |
parallel plate capacitor |
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usnavalmd Mon, 05 Jan 2009 18:22:53 GMT |
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| a capacitor was formally called a what |
condensor |
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usnavalmd Mon, 05 Jan 2009 18:22:53 GMT |
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| a device for storing electrical energy by virtue of an electrostatic field |
Capacitor |
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usnavalmd Mon, 05 Jan 2009 18:22:53 GMT |
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