In its integral form, it states that the flux of the electric field out of an arbitrary closed surface is proportional to the electric charge enclosed by the surface, irrespective of how that charge is distributed. In physics (specifically electromagnetism), Gauss's law, also known as Gauss's flux theorem, (or sometimes simply called Gauss's theorem) is a law relating the distribution of electric charge to the resulting electric field. Here, the electric field outside ( r > R) and inside ( r < R) of a charged sphere is being calculated (see Wikiversity). The electric flux is then a simple product of the surface area and the strength of the electric field, and is proportional to the total charge enclosed by the surface. Gauss's law in its integral form is most useful when, by symmetry reasons, a closed surface (GS) can be found along which the electric field is uniform. The rod in the smaller coil will pick up more clips.Not to be confused with Gause's law. Note that, with its greater number of windings, the smaller diameter coil will produce a stronger magnatism than the larger coil. Use the same arrangement with the battery, this time using the smaller diameter coil.Demonstrate that the rod, when placed within the coil, is now magnatized and will pick up paper clips, tacs, and staples.Reconfigure the wires and clips so that the battery completes the circuit with the large coil.Move the rod in and out of the coil and observe the galvanometer move in the direction of the motion.Connect the primary (larger) coil to the galvanometer using the aligator clips.If the flux through the loop is being decreased, then the induced current will be in a direction that tries to increase the flux through the loop. In other words, if the flux through the loop is being increased, then the induced current will create its own flux that will try to cancel out the increase in flux. Lenz’s Law: The induced current in a loop of wire will be in a direction that opposes the change in flux through the loop. This relationship is stated in Lenz’s Law. The negative sign indicates that the induced voltage is in a direction that creates a current that opposes the change in flux in the loop. That induced voltage around the loops causes a current to flow through the wire and that is the output current of the generator. A generator rotates a loop (actually multiple loops) of wire through a fixed magnetic field and induces a voltage around the loop by rapidly changing the flux through the loop as it rotates. Therefore changing the angle either increases or decreases the flux because the dot product depends on the sine of the angle between the vectors B and dA. Remember that flux is the integral of the dot product between B and dA. Change the angle between the surface defined by the loop and the magnetic field vector.Change the area of the loop (increase by expanding the loop, decrease by shrinking the loop).Change the magnetic field strength (increase, decrease) over the surface area.There are three ways to change the magnetic flux through a loop: The induced EMF (voltage or potential difference) around a closed loop is equal to the instantaneous rate of change (derivative) of the magnetic flux through the loop. Furthermore, the rod becomes magnatized and can be used to pick up small metal objects, like paper clips. The rod provides a direction for the current and stabilizes it. Alternatively, or additionally, the apparatus can be rearranged so that an electrical current generated from a battery is passed through the coil. This can be observed by the alternating (+) and (-) movements on the galvanometer. This in turn makes the electrons (current) in the coil move. When the rod is pushed in and out of the coils, the magnetic field around the coils is changed. Since the copper coils (refered to as a loop) contain a changing electric charge, an object placed within the electric field will become charged (magnetized). Here is described a potential lab or demonstration of Faraday's principle of electromagnetic induction. Students may wonder how transformers and generators work.
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