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Imabioperson
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I am having some trouble with discerning whether current (electrons flowing through the Tungsten), or the energy transfer as described by the poynting vector, is responsible for lighting the lightbulb.
Imabioperson said:I am having some trouble with discerning whether current (electrons flowing through the Tungsten), or the energy transfer as described by the poynting vector, is responsible for lighting the lightbulb.
They are essentially the same. The power density throughout the bulk of the filament is given by the current density (squared) and the resistivity. This quantity will be equal to the Poynting flux across the surface of the filament.Imabioperson said:I am having some trouble with discerning whether current (electrons flowing through the Tungsten), or the energy transfer as described by the poynting vector, is responsible for lighting the lightbulb.
When you say "energy transfer" are you asking about the energy transfer from the field at one point to the field at another point or are you asking about the energy transfer from the field at one point to the matter at the same point? The Poynting flux is the first, and the joule heating is the second.Imabioperson said:is it that the cross product of the two fields, ExB, is responsible for the energy transfer
Imabioperson said:I am having some trouble with discerning whether current (electrons flowing through the Tungsten), or the energy transfer as described by the poynting vector, is responsible for lighting the lightbulb.
Imabioperson said:Hi Dale,
Thank you. Although they may have an equal value, is it that the cross product of the two fields, ExB, is responsible for the energy transfer, with the source of this EM wave being related to the E field induced by the current? I simply want to know what the source of the energy is, that we see lost as the heat and light. Is it the EM wave generated by the two fields, or simply electron flow. A bit confusing to me, and thank you very much for taking the time to answer.
Electricity is a form of energy that is created by the movement of electrons. In order to turn on a light bulb, an electric current must flow through a conductive material, such as a wire. When the current reaches the light bulb, it causes a filament inside the bulb to heat up and produce light.
A light switch is connected to the circuit that provides electricity to the light bulb. When the switch is flipped, it completes the circuit and allows the electricity to flow through the wires and reach the light bulb, turning it on. When the switch is turned off, it breaks the circuit and stops the flow of electricity, turning off the light bulb.
Light bulbs have a limited lifespan because the filament inside them will eventually break after being heated up and cooled down repeatedly. This can be caused by a variety of factors, including the quality of the bulb, the amount of voltage it receives, and the number of times it is turned on and off.
Yes, in addition to electricity, light bulbs can also be powered by other sources of energy such as heat, friction, and even chemical reactions. For example, some flashlights use a battery to create a chemical reaction that produces electricity to turn on the light bulb.
The brightness of a light bulb is determined by the amount of electrical energy it receives. By adjusting the voltage or amount of current flowing through the bulb, the filament can be made to produce more or less light. This is why light bulbs with different wattages will have different levels of brightness.