If we apply a continuously changing current to a coil of wire, we will have a continuously changing magnetic field within it. Transformer designers use different techniques to prevent this as the heating is just wasted energy. In this project we will directly make use of this heating effect and try to maximise the heating effect produced by the eddy currents. Most transformers have a metallic core and will therefore have eddy currents induced into them when in use. The effects of induction are used in transformers for converting voltages in all sorts of appliances. The heat generated is proportional to the current squared multiplied by the resistance of the material. The next question asks when does the maximum flux occur and that happens when Θ is 0 degrees because when this line is horizontal then you will have the greatest number of field lines through the coil- that's one way to think about it- flux can be thought of as how many field lines will go through the coil? Another way to think of it is that since this flux is proportional to cos of the angle, you can look at the graph of cos and it has a maximum at Θ is 0 degrees and a minimum at Θ equals 90 and so this cos Θ is maximum at Θ equals 0 so that's another reason to say the maximum flux happens at Θ equals zero.When a magnetic field changes near a metal or other conductive object, a flow of current (known as an eddy current) will be induced in the material and will generate heat. So that's 1.5 times 10 to the minus 3 tesla times 0.2 square meters times cos 60 and that's 1.5 times 10 to the minus 4 webers. So the magnetic field strength is 1.5 times 10 to the minus 3 tesla and the question first of all is what is the magnetic flux through the coil? So flux is the magnetic field strength times the area of the coil times cosine of this angle between the perpendicular and the field.
Now an angle between a coil and a field is always measured between this perpendicular to the coil and the field direction so this is the angle of 60 degrees.
A coil has an area of 0.2 square meters and it's at an angle of 60 degrees, with respect to a magnetic field.
This is College Physics Answers with Shaun Dychko.
0 kommentar(er)
