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Wednesday, October 24, 2007
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Electric Field
Electric FieldIn physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field. This electric field exerts a force on other electrically charged objects. The concept of electric field was introduced by Michael Faraday.
The electric field is a vector field with SI units of newtons per coulomb (N C−1) or, equivalently, volts per meter (V m−1). The direction of the field at a point is defined by the direction of the electric force exerted on a positive test charge placed at that point. The strength of the field is defined by the ratio of the electric force on a charge at a point to the magnitude of the charge placed at that point. Electric fields contain electrical energy with energy density proportional to the square of the field intensity. The electric field is to charge as acceleration is to mass and force density is to volume.
A moving charge has not just an electric field but also a magnetic field, and in general the electric and magnetic fields are not completely separate phenomena; what one observer perceives as an electric field, another observer in a different frame of reference perceives as a mixture of electric and magnetic fields. For this reason, one speaks of "electromagnetism" or "electromagnetic fields." In quantum mechanics, disturbances in the electromagnetic fields are called photons, and the energy of photons is quantized.
A stationary charged particle in an electric field experiences a force proportional to its charge. The electric field is defined as the proportionality constant between charge and force in this relationship:
where F is the electric force on the particle, q is its charge, and E, is the electric field that the particle is in.
Electric Field Line
Electric field lines can be drawn using field lines. They are also called force lines.
(positive charge electric field)
The field lines are originated from the positive charge.
(negativ charge electric field)
The field lines end up at the negative charge.
A positive charge exerts out and a negative charge exerts in equally to all directions; it is symetric. Field lines are drawn to show the direction and strength of field. The closer the lines are, the stronger the force acts on an object. If the lines are further each other, the strength of force acting on a object is weaker.
It's Better To LEARN nothing than to KNOW nothing
lured into a deep sleep at Wednesday, October 24, 2007 0 person(s) commented while I sleep
lured into a deep sleep at Wednesday, October 24, 2007 0 person(s) commented while I sleep