Electrical element
An electric circuit, or electrical network, consists of electrical elements or components connected by conductors. The elements alter the way that electric current flows through the conductors. The concept of electrical elements is used in the analysis of electrical networks. Each element represents one of the fundamental aspects of the electrical network. The elements are:- Current source, measured in amperes - produces a current in a wire.
- Voltage source, measured in volts - produces a potential difference across two points.
- Resistance, measured in ohms - produces a voltage proportional to the current flowing through it.
- Capacitance, measured in farads - produces a current proportional to the rate of change of voltage across it.
- Inductance, measured in henries - produces a voltage proportional to the rate of change of current through it.
Any electrical circuit can be analysed if the circuit components are represented by the above elements. However, there is a distinction between elements, and the components which the elements represent.
Elements and Components
A battery provides electromotive force (emf), or voltage, in a circuit. It contains layers of chemicals that cause electrons to move in a certain direction, from its negative pole to its positive pole. It is marked with a rating of how much voltage there is across the two poles, and a (-) for the negative pole and a (+) for the positive pole.An ideal battery can thus be represented as a voltage source. In practice, a battery also has an internal resistance that is represented as a resistance in series with the voltage source.
If a wire is used to connect the two poles of a battery, electrons flow through the wire from the negative end to the positive end. (The wire will also get hot because it isn't a perfect conductor, and the battery will quickly exhaust all its power.) Thus a wire can be represented as a low-value resistor.
Current sources are often absent from basic electric circuits, and are more likely to be found in electronic circuits containing semiconductors.
A resistor is a component whose function is to regulate the current in the circuit. One common kind is a little cylinder of graphite with metal wires coming out of either end. These are painted with colored stripes that indicate the resistance, in ohms.
Another kind of resistor is a filament[?], which is a coil of metal wire that can withstand high temperature but has a finite resistance. When a current is passed through a filament, it heats up because of this resistance. Filaments are commonly used in light bulbs and heaters. They are marked with the voltage that should be applied to them, and the power, in watts, that they will then give off as light and heat. Due to the effect of heating, a filament's resistance is higher when it is hot than when it is cold.
An electric charge can be stored and then quickly released by a component called a capacitor. A common type of capacitor consists of two pieces of metal foil (or plates) with an insulator such as waxed paper between them.
If an electric charge is placed on the plates of a capacitor, it will stay there because it can't cross the insulator to the other plate. If a wire is then connected between the two plates, the charge will flow through the wire to balance the charges on the opposite plates--the capacitor is then said to be discharged.
Some capacitors look like a cylinder or blob with two wires coming out one end, and are marked to indicate their capacitance (the charge that they store per volt) in microfarads (μF), nanofarads (nF) or picofarads (pF).
Inductance in a circuit is provided by components called inductors, which are almost always built from coils of wire. Large values of inductance are obtained by forming the coil around a magnetic core, such as a lump of iron or ferrite. Inductance is also present in the windings of electric motors and generators, and to a lesser extent in any piece of wire.
A longer list of electronic components can be found in the electronics article.
"The Horror brooding over life,
they rose and reigned, they fought and fell,
the tinkling of the Camel's bell."
V
these be the whims of mortal will:
what harms and hurts I hold as 'ill:'
They change with place, they shift with race;
Each Vice has worn a Virtue's crown;
while this with that connects and blends;
where one begins, where other ends:
* Supposed to be the Prophet Elijah.
What mortal shall consort with Khizr,
What man foresees the flow'er or fruit
Anagke, Kismet, Des'tiny read
Star, Fortune, Fate, Urd, Norn or Need.
"Man's nat'ural state is God's design;"
"Man's primal Age was Age of Gold;"
drew upon Earth his earliest breath
of anguish, torture, prey and Death;
Where hideous Theria of the wild
Where horrid Saurians of the sea
to spawn her frightful monster-brood;
now reeking wet with steamy flood.
Yon glorious Sun, the greater light,
A flaming, boiling, bursting mine;
the Lover's lamp, the Swain's delight,
a corpse upon the road of night.
What reckt he, say, of Good or Ill
The blood-fed rav'ening Beast of prey,
to feed and swill, to sleep and breed,
a perfect life sans Code or Creed?
His choicest garb a shaggy fell,
His best of orn'aments tattoo'd skin
when Mays awoke to warm desire;
when Fancy lent a purer fire.
Where then "Th' Eternal nature-law
Behold his simiad sconce and own
from Beaver, Ape and Ant to build
from blast and blaze that hurt and killed;
And last came Fire; when scrap of stone
.
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