p5 investigation cwk- resistance of a lightbulb
Investigating the Factors that Affect the Resistance of Light Bulbs In this investigation I will be investigating the factors that affect the resistance of light bulbs. I will be conducting a variety of experiments to investigate this by using a range of equipment. From my results I will explain and come to a conclusion in outlining what factors affect the resistance of light bulbs. Resistance is the opposition that is created to the flow of electric current. The standard unit of measurement is Ohms (?). The resistance of a component is calculated by dividing the Voltage (V), which is measured in volts by the Current (I) which is measured in amperes. The formula beside illustrates how the resistance can be calculated. From looking at the factors that affect the resistance of light bulbs I can see that there are five factors that affect the resistance. These factors are: * The Voltage Across the Circuit * The Type of Wire * The Length of the Wire * The Area of the Wire * The Temperature of the Wire Preliminary Plan - Before conducting the experiment I had conducted a preliminary experiment. The preliminary investigation helped me analyse whether my method that I was using was suitable and indicated to me any changes that I might have to make while conducting my final results. To complete the investigation I will need an independent and dependant variable. The
Why is there resistance in wires, and when you differ things like the extent of the wire, why does the resistance alter?
Why is there resistance in wires, and when you differ things like the extent of the wire, why does the resistance alter? The cause in support of resistance in wire is because of the composition of the atoms such as copper, aluminium, of which a particular wire is made of and the plan of the atoms of these metals. When an electron passes through the wire, the electrons strike these atoms whilst making the trip from one end to the other giving opposition or resistance to the electrons. When this happens electrons stir an electromotive force such as voltage, and in hitting these atoms, also creates heat via friction of the electrons and atoms. When the wire is lengthened, the journey is considerably longer and the resistance changes. Also, the size of the wire changes the amount of resistance. That is one basis why you don't use a #22 gage lamp cord extension to supply extended power to an appliance of heavy duty. You don't have the capacity to supply sufficient electrons capable enough to run the domestic device. A enhanced way to respond to this question is through an analogy. Visualize the charge that is flowing through a wire to be water flowing through a pipe. The Rate at which the water is flowing is the current in an electrical system, how fast are the electrons moving. Resistance is what restricts the movement of the charge through the wire. The length of a pipe, the
The resistance of wire.
Aim I am going to be studying the resistance of wire. The purpose of this investigation is to see how length and thickness of wire affect the dependent variable, resistance. Prediction I predict that, as the length of the wire doubles, the resistance will also double, but as the cross-sectional area of the wire doubles, the resistance halves. This means that the length will affect the resistance more than the thickness will. Hypothesis Resistance is caused by electrons bumping into ions. If the length of the wire is doubled, the electrons bump into twice as many ions so there will be twice as much resistance. So If the cross-sectional area of the wire doubles there will be twice as many ions and twice as many electrons bumping into them, but also twice as many electrons getting through twice as many gaps. If there are twice as many electrons getting through, as there is twice the current, the resistance must have halved. This means that essaybank.co.uk I am assuming that the temperature is kept constant and that the material is kept constant. We can include this in our equations by adding a constant wweb ebw esebebs ayeb ebba neb kceb ebuk. Method Equipment needed: x Power Pack (to give varied voltage) x Voltmeter x Ammeter 5 x wires (with crocodile clips) wire of varied length and thickness Controlled variables: wwfa faw esfafas ayfa faba nfa kcfa
Investigation of the factors that affect the resistance of a wire.
Investigation of the factors that affect the resistance of a wire AIM: To investigate how the length, the cross sectional area and the material of a wire affect its resistance. PLANNING: Background information Metals have a high density of conduction electrons. The aluminium atom for example has three valence electrons in a partially filled outer shell. In metallic aluminium the three valence electrons per atom become conduction electrons. The number of conduction electrons is constant, depending on neither temperature nor impurities. Metals conduct electricity at all temperatures, but for most metals the conductivity is best at low temperatures. Resistance in electricity is the property of an electric circuit or part of a circuit to transform electric energy into heat energy by opposing electric current. Resistance involves collisions of the current-carrying charged particles with fixed particles that make up the structure of the conductors; this can be seen in the diagram below. Resistance is often considered as localized in such devices as lamps, heaters, and resistors, in which it predominates, although it is characteristic of every part of a circuit, including connecting wires and electric transmission lines. Diagram 1: The collisions of electrons with ions in a circuit Electron Ion direction in which the electron is moving Here the electron is going to
A little bit about the life and times of Georg Simon Ohm:
A little bit about the life and times of Georg Simon Ohm: Georg Simon Ohm was a German physicist born in Erlangen, Bavaria, on March 16, 1787. As a high school teacher, Ohm started his research with the conduction of electricity, then recently invented electric cell, invented by Italian Conte Alessandro Volta. Using equipment of his own creation, Ohm determined that the current that flows through a wire is proportional to its cross sectional area and inversely proportional to its length. Using the results of his experiments, Georg Simon Ohm was able to define the fundamental relationship between voltage, current, and resistance. These fundamental relationships are of such great importance, that they represent the true beginning of electrical circuit analysis. Unfortunately, when Ohm published his finding in 1827, his ideas were dismissed by his colleagues. Ohm was forced to resign from his high-school teaching position and he lived in poverty and shame. However, his research efforts gained a lot of support outside of Germany. In 1849, Georg Simon Ohm was finally recognized for his efforts by being appointed as a professor at the University of Munich. OHM: Symbolised as ?. The SI UNIT of electric RESISTANCE, defined as the resistance between two points on a conductor through which a current of one ampere flows as a result of a potential difference of one volt applied between
Investigating The Effect Of Resistance On A Capacitor Circuit
Investigating The Effect Of Resistance On A Capacitor Circuit Aim: to see what affects the rate of discharge on a capacitor. PLANNING Hypotheses: ) The bigger the capacitance, the longer amount of time it will take for the capacitor to discharge through a resistor. 2) The bigger the resistance, the longer amount of time it will take for the capacitor to discharge. Therefore I expect that capacitance is directly proportional to the rate of capacitor discharge and also that resistance is directly proportional to the time taken to discharge a capacitor Capacitors and Capacitance: A capacitor is an electrical device that can store energy in the electric field between a pair of closely spaced conductors or plates which are separated by an insulator. When voltage is applied to the capacitor, electric charges of equal magnitude, but opposite polarity, build up on each plate. The larger the capacitance the more charge it can store. Capacitace is the ability of a capcitor to store electrical charge and it is measured in farads (F). The capacitance used in our investigation, however, was measured in microfards (µF). Resistors and Resistance A resistor is a component of an electrical circuit which produces resistance, or in simpler terms, it restricts the flow of electric current in a circuit. There are many different values that resistors can have, and these values can
To investigate the relationship between the structure and heat provided by combustion of a range of alcohols.
COURSE WORK PIECE 1: INVESTIGATION OF THE COMBUSTION OF ALCOHOLS HARRY HUDSON 10 U 25/10/02 AIM: To investigate the relationship between the structure and heat provided by combustion of a range of alcohols. INTRODUCTION: In this investigation I will be burning a range of alcohol in a method known as calorimetry. This will allow me to see the amount of energy produced by each alcohol, and then look at the structure of the alcohol and investigate why an amount of energy is produced for each alcohol. Before I go on with the experiment there are several factors that must be first understood. What is an alcohol? The definition of an alcohol as taken from Richard Harwood's Chemistry textbook is "a series of organic compounds containing the functional group - OH." The - OH group, called a hydroxyl group is what defines the compound as an alcohol. The alcohol compounds are very similar to the alkanes, however alcohols contain one oxygen atom, creating the hydroxyl group, and making the alkane an alkanol (alcohol). As the hydroxyl group makes the compound different to an alkane, the hydroxyl group is seen to be "functional". The formula for alcohol is: In this investigation I will look at the first five alcohols. These are methanol, ethanol, propan-1-ol,
Choosing a light source
Task 1 As a part of this tasks, I will conduct a survey to show the way in which light is produced in the following types of lights;- * Domestic * Industrial/commercial * Outdoor Domestic For the domestic lights, I have used house hold light bulbs which are made from a tungsten wire. the tungsten wire is placed inside a glass so that when it is heated, it does not react with oxygen to produce a oxide. The diagram below shows a tungsten light bulb. the voltage that is passed though the power supply goes to the tungsten wire and interferes with the atomic structure of the electrons on the atom of the tungsten. this is because the voltage is energy, and this energy moves the electrons for the orbital of the nucleus of the atom. If one of the electrons in the shells of the atom move out of place, then this must be replaced by another one straight away to keep the orbital of the electrons around the nucleus right. So to do this, one of the electrons from the outer shell of the atom jumps in to the place of the atom that was knocked out by the voltage. In doing so, a photon of energy is passed out. This photon is the light we see when we turn on a bulb. The tungsten metal is a good metal to be used for this kind of job. This is because tungsten has a high atomic number. This means that there are more shells of electrons. More electrons would mean that more photons
Investigating resistance when altering thickness of wire / length of wire
Investigating resistance when altering thickness of wire / length of wire The circuit: Diameter: * Wires of different thicknesses are used. * In order to produce a straight line graph: plot Resistance (y axis) against (1/A) x-axis where A is the area of the wire. To do this: * * Measure the diameter of each wire, work out the area by doing (pi x d2)/4 then do 1/A where A = area of cross section. * Record the current and voltage for each of the wires used keeping the same circuit for each wire. Work out resistance by doing V/I where V is the voltage and I is the current. * For different wires of the same material, the resistance R of each wire is directly proportional to 1/A where A is the cross section area of the wire or R is inversely proportional to A. This means that as area is doubled, resistance is halved and when area is tripled the resistance is a third of what it was before. A wider wire has lower resistance because more electrons can get through per second (current is higher) than if the wire was thin. Length: * Different lengths of the same type of wire are tested. * Voltage and current is measured for each length of wire. In your table put voltage, current, resistance, and length (in metres). Work out resistance by doing V/I where V is voltage and I is current. * The graph shows that resistance is directly proportional to length so as length is
Investigating the factors affecting the current flowing through a wire.
Anna Belcher Physics Investigating the factors affecting the current flowing through a wire Background Knowledge In this investigation I will be measuring the current flowing through a length of wire. A current is a flow of electric charge and will only flow when there is a complete circuit and a voltage. All substances are made of atoms which consist of a nucleus surrounded by moving electrons. In metals the outer electrons are 'free' and can be made to flow in one direction. If a potential difference is applied to a wire in a complete circuit a current will flow because the 'free' electrons will move. The electrons will move away from the negative side of the power supply and towards the positive side although the conventional current goes against the flow of electrons. The diagram below shows the electron flow. There are two types of current that can flow around a circuit. Direct current is when the charge flows continuously in one direction. An alternating current is when the current flows alternately in both directions (positive to negative and vice versa). This can be shown on an oscilloscope as shown in the diagram below. The current is a measure of the number of charges per second (Cs-1) and is measured in Amperes (A). A = 1Cs-1 An ammeter is used to measure the current and does this by measuring the number of charges passing a point per second. The equation to
