An Investigation Into Electrical Resistance :: essays research papers

Background KnowledgeResistance, in electrical energy, is a property of any object or means to resist the head for the hills of an electrical current. The quantity of resistance in an electric circuit determines the nitty-gritty of current plying in the circuit for any stipulation potential difference applied to the circuit. The resistance of an object is determined by the nature of the substance of which it is composed, its resistivity, accounting for its dimensions and its temperature. Resistivity is expressed in terms of Ohms / cm3 at 20C. An electrical conductor is any material that offers little resistance to the flow of an electric current. The difference between a conductor and an insulator, which is a slimy conductor of electricity, is one of degree rather than kind, because all substances conduct electricity to some extent. A good conductor of electricity, such as capital or copper, may have a conductivity billions of times as great, or more, as the conductivity of a g ood insulator, such as glass or mica.MethodWe were influence the task of investigating the factors that cum into play when determining the resistance of a piece of cable. We would be provided with the indispensable apparatus needed to carry out the investigations. The basic setup would regard a circuit with a set of cells connected in serial with an ammeter and the piece of wire being investigated, and a voltmeter connected in analog with the wire. The ammeter is placed in series with the wire. An ammeter has a low resistance, so that it introduces as little extra resistance as possible into the circuit. The voltmeter is connected in parallel with the wire. Voltmeters have a high resistance, so the current they put one over is usually negligible.We decided on the variables that could affect the resistance of a wire&61623 Length of the wire&61623 Thickness of the wire&61623 The material used as the wire&61623 TemperatureWe were to investigate as many of these factors as possi ble devoted a limited period of time. We would carry out a set of experiments where in each one we changed one variable while tutelage the others constant. In each case we would have to measure the current issue through the circuit and the potential difference across the wire given these the resistance could be calculated using the formula R=v/i, where R is the resistance in Ohms, v is the potential difference in Volts, and i is the current in Amperes.