Related Keywords

No Related Keywords

Register NowHow It Works Need Essay Need Essay
SCIENCE COURSEWORK: RESISTANCE OF WIRE EXPERIMENT
1 User(s) Rated!
Words: 2670 Views: 957 Comments: 0
Risk Assessment To keep the experiment safe I shall keep electrical conductors away from the plug sockets. I will take care not to hurt myself or anybody else with the crocodile clips. I will also not turn the power socket on full so as that the wire does not burn or set fire to any surrounding objects or burn anybody. Preliminary work Firstly I assembled the apparatus as shown in the diagram below. For the wire I used 34 standard wire gauge wire. I then took measurements placed the two wire ends marked with an X...
Voltmeter reading by the Ammeter reading, giving me the resistance. This experiment would then be repeated three times so as to determine any anomalous results.

Diagram of apparatus for alternative experiment

I predict that the readings on the Voltmeter and Ammeter would be higher but when divided and the resistance worked out that the resistance would be very similar to that of the results worked out in my main experiment. This would be a useful experiment to carry out alongside my other to support my theory and satisfy my aim.

Become A Member Become a member to continue reading this essay orLoginLogin
View Comments Add Comment

Electromagnetism experiment: Introduction: I...Electromagnetism experiment: Introduction: I start the introduction with a question: Will increasing current in an electromagnet increase the power of the electromagnet? The electromagnet we will be making is a very primitive one compared to that of the complexity of modern electromagnets found in machinery, but the way it works is almost identical. Electromagnetic technology is extremely complex and because it is an electromagnet, the higher the current, the stronger it becomes, and with this an electromagnet can become incomprehensively strong. Such an example is that used in theme park rides to stop moving parts etc. these electromagnets are in fact so strong that when uncovered, if you were to stand with a spanner in your hand 10 metres away, it would pull the spanner out of your hand along with the rest of your arm! To understand fully how an electromagnet works read on"¦ Background information: When an insulated wire is wrapped around some form of iron, nickel or cobalt core, whether it be a nail or a u-shaped core, and then attached to a power supply it creates an electromagnet capable of picking anything from the size of a paperclip right up to anything as big as a car and bigger! Obviously such a primitive electromagnet would not be able to lift a car but a more advanced one would have no problem lifting a car. When the power supply is cut off the items picked up will fall off. This is because the current creates a magnetic field and this magnetic field is lost when it is turned off. When a current channels through an electromagnet a magnetic field is produced. This field is built up in a series of concentric rings. The diagram below shows a cross-section of a wire's magnetic field. As you come further away from the wire the field weakens and spreads further apart from each ring. There are four main factors that affect the strength and size of this field: Current/voltage Number of coils Size and shape of core Material of core iron being the strongest For example: two coils wrapped around the iron core would induce twice the strength of one coil. By this I mean that each coil will have twice the strength of one coil on it's own. Below shows a single coil's magnetic field. When two are present these rings become double the size creating a considerably larger and stronger field. Magnets are formed when certain substances iron, nickel and cobalt cool. Normally when a non-magnetic substance crystallises the atoms point in random directions. Now because of the properties of the aforementioned substances their atoms point in similar directions at each end of the magnet. These are called domains. This is because of the nature of the earth's gravitational field. Each side of the magnet's atoms, point in opposite directions. Each domain is known as either the south or north pole. Each end of the magnet is where the strongest part of the magnetic field coincides. The experiment in hand is simple. A piece of wire will be wrapped around an iron nail or some form of iron-based core where each end of the wire is attached to a circuit consisting of a power source and an ammeter. Our group will be testing the power of the magnet varying the power of the current around the circuit. We will be testing the strength from 0 to 5 amps. My prediction is that when the current is increased in turn so does the strength of the electromagnet. I believe this because an electromagnet needs an electrical input in order to create a magnet, so logically if that electrical input is increased then it becomes stronger. The aim of this project is to test the power of an electromagnet when the current is increased or decreased. Preliminary experiment The initial experiment is just to test the strength by seeing how many nails are picked up at varying strength of current. We will also be testing the strength when the amount of coils are increased or decreased. Apparatus: Crocodile clip x 2 Red insulated wire x 2 Black insulated wire x 1 Ammeter U-shaped iron core 1: An electrical wire will be coiled around a soft-iron core 30 times. 2: Crocodile clips will be connected to yellow connecting wires at each end. 3: These together with the ammeter will be connected up to the power supply as shown in the circuit diagram. 4: A fixed amount of nails will be poured over the electromagnet with the power switched on 5: The power will be turned off. All of the iron filings that drop off will be weighed. I will vary only the current in this experiment. All other factors will be kept constant. I will measure the amount of iron filings at 1,2,3,4 & 5 amps. I will repeat each experiment three times for accuracy. Safety Precautions We will make sure that there is no bare insulation or any water near any electrical equipment to prevent electrical faults and dangers I might need to repeat some results that show no correlation to the other results, if they are drastically wrong. Factors Affecting The Experiment: 1:Current-This will change in one experiment. This will be kept constant by observing the ammeter and correcting any fluctuations on the D.C power pack. 2: Magnetic strength of the Soft-Iron Core. This will affect the power of the electromagnet. It will be kept constant by using the same soft-iron core. 3: The way in which the wire is coiled. If the coils are coiled towards end, then one end will be more powerful than the other, and affect the results. I will try to keep the shape of the coils uniform. 4:The way in which, the nails are shaken. The harder the magnet is shaken, then the more nails will be dropped, and the more the results will change.   

Electromagnetism experiment: Introduction: I start the introduction with a question: Will increasing current in an electromagnet increase the power of the electromagnet? The electromagnet we will be making is a very primitive one compared to that of the complexity of modern electromagnets found in machinery, but the...

Words: 1040 View(s): 226 Comment(s): 0
For many centuries, scientists have been...For many centuries, scientists have been puzzling over the question "What is everything made of?". There have been numerous theories and hypotheses drawn up over the millennia, but only one can be correct. This is atomic theory "“ that everything is composed of atoms, which is the smallest any one element can be and cannot be broken up any smaller. Of course, no one person has ever just clicked his or her fingers and exclaimed Archimedes-fashion "Eureka!" and settled the score forever, but the theory today has been based upon the work of many great scientists over time. In this essay I shall look at just a drop in the ocean as far as these are concerned, on the subject of changing atomic models. John Dalton 1766-1844 developed the first useful atomic theory of matter around 1803, developing a hypothesis that the sizes of the particles making up different gases must be different. He came up with the four following points: "¢ All matter consists of tiny particles "¢ Atoms are indestructible and unchangeable - atoms of an element cannot be created, destroyed, broken into smaller parts or transformed into atoms of another element. Dalton based this hypothesis on the law of conservation of mass and on centuries of experimental evidence. "¢ Elements are characterized by the mass of their atoms. All atoms of the same element have identical weights, Dalton asserted. Atoms of different elements have different weights. With the discovery of isotopes, however, the statement was amended to read, "Elements are characterized by their atomic number". "¢ When elements react, their atoms combine in simple, whole number ratios. This suggested a practical strategy for determining relative atomic weights from elemental percentages in compounds. Experimental atomic weights could then be used to explain the fixed mass percentages of elements in all compounds of those elements! Some of the details of Dalton"s original atomic theory are now known to be incorrect. But the core concepts of the theory that chemical reactions can be explained by the union and separation of atoms, and that these atoms have characteristic properties are foundations of modern physical science. One classic diffraction experiment, which examined diffraction of alpha particles helium nuclei containing two positive charges by a thin foil made of gold metal, was conducted in 1911 by Hans Geiger and Ernest Marsden at the suggestion of Ernest Rutherford. Geiger and Marsden expected to find that most of the alpha particles travel straight through the foil with little deviation, with the remainder being deviated by a percent or two. This thinking was based on the theory that positive and negative charges were spread evenly within the atom and that only weak electric forces would be exerted on the alpha particles that were passing through the thin foil at high energy. What they found, to great surprise, was that while most of the alpha particles passed straight through the foil, a small percentage of them were deflected at very large angles and some were even backscattered. Because alpha particles have about 8000 times the mass of an electron and impacted the foil at very high velocities, it was clear that very strong forces were necessary to deflect and backscatter these particles. Rutherford explained this phenomenon with a revitalized model of the atom in which most of the mass was concentrated into a compact nucleus holding all of the positive charge, with electrons occupying the bulk of the atom"s space and orbiting the nucleus at a distance. With the atom being composed largely of empty space, it was then very easy to construct a scenario where most of the alpha particles passed through the foil, and only the ones that encountered a direct collision with a gold nucleus were deflected or scattered backwards. Of course, these are just two of the many findings in this field of scientific research, but what they have helped prove is the basis on all elements and their atoms "“ only now can scientists predict and understand reactions to such a level of accuracy.   

For many centuries, scientists have been puzzling over the question "What is everything made of?". There have been numerous theories and hypotheses drawn up over the millennia, but only one can be correct. This is atomic theory – that everything is composed of atoms, which is the smallest any one...

Words: 687 View(s): 248 Comment(s): 0