# Why is the relationship between electricity and magnetism important

### Relation between electricity and magnetism

This transformation between electric and magnetic fields is perfectly . This leads to a very important point - Electricity and Magnetism are. Electricity is a form of electrical energy that is transmitted through the wires for Physics>> Magnetism >> Relation between electricity and magnetism The relationship between electricity and magnetism is called electromagnetism. The interaction between magnetism and electricity is called electromagnetism. What Are the Two Major Components of an Atom?.

While he was working on these equations, it occurred to Maxwell that if one could Similar to the way an oscillating magnetic field can induce an electric current. Then, the oscillating electric field would produce a magnetic field. And so on, in an endless cycle. Maxwell was able to show that, if such a thing were to be created, the electric and magnetic fields would oscillate at right angles to each other one wave going up and down, the other going in and out and would travel together while shifting their energy back-and-forth as they constantly and dynamically regenerated each other.

In other words, you would have electric and magnetic fields existing by themselves, with no charges, no magnets, and no masses. Maxwell calculated that the speed of this wave would be: If we insert the values given earlier, we have: Which is the speed of light.

Although this did not prove that light was the mutually perpendicular electric and magnetic wave couplet which Maxwell envisioned, it was certainly suggestive, and Maxwell did suggest that light was an electromagnetic wave.

Maxwell's picture of a light wave is illustrated below. Maxwell died rather young, at the age of 48, and it was left to others to extend his work. Throughout the 's and 's his equations were applied to a number of problems in electromagnetism mostly by British physicists, because Maxwell's work did not really catch on outside the British Isles until It gradually became clear to a number of people that Maxwell's equations predicted that electromagnetic waves should always be produced any time you had electric charges under acceleration.

The Relationship between Magnetism and Electricity

In rough terms, accelerating charges always "shed" electromagnetic waves more-or-less like a speedboat sheds water waves. Did this mean that ordinary electric circuits were giving off invisible waves as the electricity moved around? According to Maxwell, it seemed that they ought to be. To make a long story short, a few people did begin looking for invisible waves, and in the German physicist Heinrich Hertz one of the few German physicists who thought maybe Maxwell had something here discovered radio waves.

This created quite a sensation, and from that point onward Maxwell's theory of electromagnetism was established as the best one. This property of moving charges is why the airlines usually request that you turn off stereos and so forth during takeoffs and landings.

If it uses electricity, then it produces radio noise at some level, and that is that. This can interfere with air navigation. I sometimes overhear fellow passengers grumbling that it's silly, their portable CD player isn't a radio so what's the problem Electromagnetic waves form an entire spectrum, as seen in the figure at right. Back to our story.

## Magnetic Field Basics

The search for the ether Probably the most puzzling result was the now-famous Michelson-Morley experiment of Albert Michelson and Edward Morley were professors at Case Western University in Cleveland, and they wanted to detect the motion of the Earth through the ether by looking at the speed of light as it moves in different directions.

Michelson and Morley hoped to measure subtle differences in light interference patterns which would allow them to tell if the universal ether was standing still or flowing in some way. Alas, to their immense puzzlement, they couldn't detect any differences in the speed of light at all!! Whether the Earth was moving in the same direction as the light in their experiment, or opposite to it, or at right angles to it, the result was always the same: Natural electricity makes lightning flashes and the signals that flow along our nerves.

Magnetism is electricity's close cousin. Some materials, such as iron, are attracted to magnets; while others, such as copper, are not.

We use the idea of "magnetic fields" to show how objects move when they are near magnets. Magnets have north and south poles. Two poles that are the same like north and north push each other apart.

Two poles that are not the same a north and a south pull each other together. Electricity and magnetism are really two different parts of a single force. A moving magnet makes electricity and an electrical current makes a magnetic field. We use these facts to build motors and generators.

Magnetic fields and electrical currents make waves of energy that flow outward into space at the speed of light which is very, very fast! These waves of energy are called " electromagnetic radiation ". There are six kinds of electromagnetic radiation. The light that we see with our eyes is one kind. Ultraviolet and infrared "light" are invisible to us, but some animals and insects can see them.

### Electricity & Magnetism

Important applications range from the largest power plants, to electric motors, down to the nanoscale write heads in our laptop hard drives. In contrast, the physics of ordered electron spin transport a spin-polarized current has become important only relatively recently. The new field of spintronics [1] is based on the ongoing prediction, discovery, and interpretation of additional interactions between electricity and magnetism that follow from the flow of spin-polarized electrons.

Writing in Physical Review Letters, Shengyuan Yang and colleagues from the University of Texas, Austin, present a theoretical description and measurements of a new spintronic interaction: So far, spintronic interactions have mainly been studied in devices made from layered ferromagnetic metal films, where the layers are thin enough that flowing electron spins carry magnetic information from layer to layer without drastic realignment.

The most dramatic example is the finding that the electrical resistance between two magnetic layers depends on their relative magnetic orientation. The effects of spin transfer torque, such as precession and switching of magnetism in small junction devices, have been measured under a wide variety of conditions.

The complementary effect, spin pumping [6]occurs when the dynamics of the magnetization in the layers drives a spin current in the device.

The consequences of spin pumping are more difficult to observe than those of spin transfer torques but are still well established experimentally [7, 8]. Spintronic effects are not only found in multilayer structures. For example, in single-layer magnetic nanowires, the analog to giant magnetoresistance is domain-wall resistance: A current in a nanowire can also move a domain wall via the same spin transfer torques that causes precession and switching in multilayers [9—11].

As electrons flow through a ferromagnet, their spins tend to align with the magnetization. When they pass into a region of nonuniform magnetization, such as a domain wall, the electron spins rotate to stay aligned with the local magnetization direction.

A reaction torque on the changing magnetization in the domain wall can cause the pattern of magnetization at the domain wall to move in the direction of the electron flow.

Several theoretical groups [12—15] have predicted the existence of a new effect that is both complementary to current-induced domain-wall motion and also analogous to spin pumping in layered structures: