Ramblings on the open wire feedline multiband antenna Christopher Scott W4NEQ Bowling Green, KY I use an old favorite multiband antenna on forty and eighty meters - the center-fed inverted V dipole, fed with true open wire feedline -sometimes known as "tuned feeders".
If an electron is all made of one kind of substance, each part should repel the other parts. Perhaps we should say that the electron is just a point and that electrical forces only act between different point charges, so that the electron does not act upon itself.
All we can say is that the question of what holds the electron together has produced many difficulties in the attempts to form a complete theory of electromagnetism.
The question has never been answered. We will entertain ourselves by discussing this subject some more in later chapters. As we have seen, we should expect that it is a combination of electrical forces and quantum-mechanical effects that will determine the detailed structure of materials in bulk, and, therefore, their properties.
Some materials are hard, some are soft. We shall consider later how some of these properties come about, but that is a very complicated subject, so we will begin by looking at the electrical forces only in simple situations.
We begin by treating only the laws of electricity—including magnetism, which is really a part of the same subject. We have said that the electrical force, like a gravitational force, decreases inversely as the square of the distance between charges.
But it is not precisely true when charges are moving—the electrical forces depend also on the motions of the charges in a complicated way. One part of the force between moving charges we call the magnetic force.
It is really one aspect of an electrical effect. We find, from experiment, that the force that acts on a particular charge—no matter how many other charges there are or how they are moving—depends only on the position of that particular charge, on the velocity of the charge, and on the amount of charge.
The important thing is that the electrical forces from all the other charges in the universe can be summarized by giving just these two vectors. Their values will depend on where the charge is, and may change with time. Furthermore, if we replace that charge with another charge, the force on the new charge will be just in proportion to the amount of charge so long as all the rest of the charges in the world do not change their positions or motions.
In real situations, of course, each charge produces forces on all other charges in the neighborhood and may cause these other charges to move, and so in some cases the fields can change if we replace our particular charge by another. We know from Vol. I how to find the motion of a particle if we know the force on it.
One of the most important simplifying principles about the way the fields are produced is this: It holds also for magnetic fields. This principle means that if we know the law for the electric and magnetic fields produced by a single charge moving in an arbitrary way, then all the laws of electrodynamics are complete.
If it had only turned out that the field produced by a single charge was simple, this would be the neatest way to describe the laws of electrodynamics. I and it is, unfortunately, rather complicated. It turns out that the forms in which the laws of electrodynamics are simplest are not what you might expect.
It is not simplest to give a formula for the force that one charge produces on another.
It is true that when charges are standing still the Coulomb force law is simple, but when charges are moving about the relations are complicated by delays in time and by the effects of acceleration, among others.
As a result, we do not wish to present electrodynamics only through the force laws between charges; we find it more convenient to consider another point of view—a point of view in which the laws of electrodynamics appear to be the most easily manageable. We have defined them in terms of the forces that are felt by a charge.
We wish now to speak of electric and magnetic fields at a point even when there is no charge present. It is a vector field. Returning to the electromagnetic fields—although they are produced by charges according to complicated formulas, they have the following important characteristic: With only a few such relationships in the form of differential equations we can describe the fields completely.
It is in terms of such equations that the laws of electrodynamics are most simply written. There have been various inventions to help the mind visualize the behavior of fields.THE TRUTH ABOUT IGNITION WIRE CONDUCTORS CARBON (SUPPRESSION) CONDUCTORS.
Carbon conductors were used in original equipment ignition wires by most vehicle manufacturers, and still in the majority of stock replacement wires. ABB-Electrical Installation Handbook 6th Edition - Ebook download as PDF File .pdf), Text File .txt) or read book online.
ABB Electrical Installation Handbook. The total length of the wires will affect the amount of resistance. The longer the wire, the more resistance that there will be. There is a direct relationship between the amount of resistance encountered by charge and the length of wire it must traverse.
Aluminium conductor steel-reinforced cable (ACSR) is a type of high-capacity, high-strength stranded conductor typically used in overhead power urbanagricultureinitiative.com outer strands are high-purity aluminium, chosen for its good conductivity, low weight and low urbanagricultureinitiative.com center strand is steel for additional strength to help support the weight of the conductor..
Steel is higher strength than aluminium which.
Electrical wire sizes & gauges: These Tables of Electrical Service Entry Cable Sizes, Electrical Circuit Wire Diameters, Circuit Ampacity, Allowable Voltage Drop, & Wire Size Increase based on Run Length assist in determining the electrical service size or other required electrical wire sizes at buildings. ABB-Electrical Installation Handbook 6th Edition - Ebook download as PDF File .pdf), Text File .txt) or read book online. ABB Electrical Installation Handbook. Resistance is directly related to the length of a wire. Greater the length more the resistance and hence more heat loss. The length of a wire affect resistance because if a long wire is used in an.
- Relationship Between the Resistance and the Length of a Wire Aim: To find the relationship between the resistance of the wire and the length of the wire Background Factors: i. Temperature: If the wire is heated up the atoms in the wire will start to vibrate because of their increase in energy.
A bunch of positives would repel with an enormous force and spread out in all directions. A bunch of negatives would do the same. But an evenly mixed bunch of positives and negatives would do something completely different.