In this paper, we talk about what is the electromotive force power source and what is its relationship with other parameters of the circuit.Just note, despite the fact that in everyday life we are successfully using electrical appliances, many laws have been derived empirically and taken for granted.It's one of the reasons for excessive complexity definitions.Unfortunately, even the electromotive force, the fundamentals of electricity, lit so that a person unfamiliar with electricity, to understand something quite difficult.We explain this issue by using understandable terms and examples of each.
directional motion of charged particles in a conductor is called "electric current".As you know, all the objects of our material world composed of atoms.For ease of understanding, you can assume that each atom is represented in the form of reduced millions of times a model of the solar system: is located in the center of the core, and at different distances from it in circular orbits of the electrons revolve.
means of any external influence in the conductor forming a closed loop, creates an electromotive force and an electric current.Exposure "beats" valence electrons from their orbits in atoms, so the formation of free electrons and positively charged ions.
electromotive force is needed in order to "force" the charges to keep moving through the conductor and the circuit elements in a certain direction.Without it, the current almost immediately extinguished.To understand what exactly is the electromotive force, will allow the comparison of electricity and water.Straight pipe - a conductor.Two of its sides it goes into the water bodies.As long as the water levels are equal and there is no deviation, the liquid in the pipe is stationary.
Obviously, to get her to move in three ways: to create a height difference (bias or amount of fluid in the reservoirs) or force pump.An important point: when it comes to vertical drop (potential difference), it means the stress.For EMF same movement "forced" because the outside forces affecting, non-potential.
Any source of electric current has EMF - the same force that supports the movement of charged particles (in the above analogy, causes the water to move).It is measured in volts.The name speaks for itself: EMF characterizes the work of a chain attached to a portion of external forces that perform the movement of each unit charge from one pole to another (between terminals).It is numerically equal to the ratio of the work of external forces attached to the largest roaming charge.
Indirectly need EMF source can be derived from the law of conservation of energy and properties of the conductor.In the closed circuit work field to move the charges is zero.However, the conductor heats up (and the stronger, the more current is passed through it at a time).Conclusion: the circuit should be a fraction of external energy.These outside forces - a magnetic field generators constantly excites electrons;the energy of chemical reactions in batteries.
electromotive force induction was first observed experimentally in 1831 by physicist Faraday.He found that the conductor lines of tension permeates the changing magnetic field, an electric current.Exposure to field reports of the outer electrons in the atoms of the missing energy to them, causing them to break away and start moving (there is current).Of course, the direct motion of the particles does not exist (how can not remember the relativity axioms of Electrical Engineering).Rather, the exchange takes place between particles of neighboring atoms.
electromotive force developed is - it is an internal characteristic of any power source.
