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The inverse square law applies when the sphere's outer surface is the important surface for the consideration. Here the important thing is the surface at any given distance that the current passes through. So, in the picture, the total current passing each black line will be the same. Each black line cuts the sphere making a circular disk. The areas of these ...

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The electric field just above the surface is defined as force on unit charge so youbarecnot allowed to take a disc from the surface and find for other charges thats untrue .the same thing is applicaple to all points outside or inside conductor .exactly on the surface the electric field function is dicontinuous inside 0 and outsid the linit when you ...

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The net electric field inside a conductor is zero because it is not just the field generated by the surface charges, it is the sum of that with the external electric field. Remember that in order to polarize a material like this you need to put it in an external electric field. This electric field causes the charges of opposite sign to accumulate on opposite ...

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An important property of conductors is that every point inside it has no net electric field. This is achieved by conductors by rearranging the charges on the surface in such a way that every point inside the conductor has no net field. If the conductor is not a perfect sphere in shape, the charge could be distributed non-uniformly to achieve this. You could ...

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The atomic magnetic dipoles in a ferromagnetic material experience a torque that tends to line them up with the crystal axis and another which tends to line them up with any magnetic field. At normal temperatures they can often maintain such an alignment. If the field has a gradient they can also experience a net force. If a ferromagnetic bar is lined up ...

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In the absence of a power source, there can be no electric field inside the material of a conductor. Any such field would move fee electrons around until there was no more field. Any charge inside a cavity in a conductor will induce an equal but opposite charge on the inner surface of the conductor. That is required by Gauss's law. The distribution of ...

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Its most probably due to the electrostatic shielding which says the what happens inside the shell will not get affected by outside , though i dont have a proof of this fact.

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A battery pulls electrons from the positive terminal and puts them on the negative terminal. The charge then distributes itself throughout the external circuit so that the line integral of the electric field from one terminal to the other (the potential difference) is the same for any path taken through the circuit. For a uniform length of wire with ...

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What is the potential difference across the resistor? You may say it is ϵ=ΔV=IR. But how can you be sure? In answering it you assumed that The resistor is made of circular wire. You also assumed that the electric field in it is uniform. And that the direction of the field is along the wire. Actually, none of those assumptions are made. We simply measure the ...

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My initial intuition after watching this video was that Derek's claim was technically true but only for an uninteresting reason. Namely, he stated that the lamp will light up once any current at all flows through it. Well, of course an infinitely sensitive amperemeter will react to the flip of the switch with the speed of light! (It will probably react to ...

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The number of electrons does effect the scattering rate, but that is not significant for these metals. Rather, their scattering is generally dominated by phonons, and at lower temperatures, defects. So to a first approximation, we can take the scattering rate to be fixed. Then, the conductivity (i.e. inverse resistivity) is proportional to electron number. ...

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