The Strength Of An Electromagnet Essay Research

  • Просмотров 127
  • Скачиваний 5
  • Размер файла 15
    Кб

The Strength Of An Electromagnet Essay, Research Paper The strength of an Electromagnet Planning Experimental procedures "h The quantity that I am intending to investigate in my experiment is the strength of the electromagnet "h The factors that affect the strength of an electromagnet are: The temperature, current, length of the core, diameter, the thickness of the wire used for the coils, how tightly the coils of wire are wrapped around, the material and also the number of turns on the electromagnet. "h I am only going to vary current in the experiment, all the other factors I will keep constant "h I have chosen to vary current because, the more turns there are, the more powerful the magnet becomes and therefore the more domains there are. The thicker the

diameter is, the more domains there are in the middle and therefore the stronger the electromagnet becomes. The higher the temperature is, the easier it is for the domains to be able to turn and line up. If you use a thinner wire it will cause more resistance in the experiment. All of these factors will change the strength of the electromagnet. "h I decided to do current, as the others were more difficult to do "h I believe that when I do the experiment, proportionally as the current increases, the strength will increase. Force (N) Current (A) "h I have made this prediction because as you increase the current, you will induce more domains to line up- and if its proportional, you would then double your current which would therefore double the domains (force). If you

were to cut a magnet in half, it doesn¡¦t destroy it, in actual fact two magnets are created. If you wanted, you could continue cutting the magnets in half each time therefore making the magnets smaller and smaller. In theory, if we used an extremely sharp, but still small blade, we would be able to on cutting magnets in half until we reached a limit-this would be called a domain and is about 1/1000th mm long and would consist of about 10 thousand million atoms. An unmagnetised iron would look like this: Using the current in the coils, you would be able to re-align some of the domains. If you did this and as a result more of the domains were pointing in the same direction, then the iron would have become a weak magnet. A weak magnet would look like this: When you switch off the

current, the domains would return back to a random set up. Obviously, if you were to line more domains up, the magnet would bcome much stronger, until you were to reach a state where you had aligned all the possible domains up. A fully magnetised magnet would look like this: "h Apparatus used: An electromagnet, powerpack, variable resistor, ammeter, an iron bar and an electric balance. The following diagram is how we set the experiment up: "h To measure the strength of the electromagnet, first of all we had to weigh the iron bar. We then switched the current on to flow through the circuit. By taking a range of different readings off both the balance and the ammeter, we established that as you increased the amount of current, the iron bar got lighter. This is because the

electromagnet was getting stronger, pulling the iron bar up and taking the pressure off from the electric balance. "h First of all I will set up the apparatus as planned, and I will take readings ranging from 6A to 0.5A. Then checking the variation in the weight of the iron bar. I did some preliminary experiments so that I could find out the range of the current, and how much voltage was needed in the experiment, and also exactly how far the electromagnet should be away from the iron bar. "h I did a preliminary experiment before the actual experiment "h I tested what was a safe current. I found out that a current up to six amps was satisfactory. We also tested what was a safe distance for an electromagnet from the iron bar-ten centimeters was too far, two