Resistance of a Wire
Resistance of a Wire Plan Aim To find out how length affects the resistance of a wire. Introduction In this investigation I will be looking at the effect length has to resistance in a wire. The wire I will be using is Nichrome Wire an I will be discussing on what resistance is, what affects resistance an how it can be controlled Background Information All things are made up of atoms and are made up of three ions, protons electrons and neutrons. Protons are positively charged, and are found in the nucleus of an atom along with neutrons that have no charge. Electrons are found in rings surrounding the nucleus of an atom. The electrons on the outer most rings in the atoms can sometimes become loose in some materials, eventually splitting into single free electrons. These electrons can move around freely, passing into the next atom and moving in random directions. Voltage is the measure of the electrical status or potential between two points. Voltage causes all these free electrons that are moving around in random directions to form a line and flow in one direction. Voltage can be measured by a voltmeter and in the unit of volts (V) When the flow of electrons is formed, it can pass through materials that will allow it to. When the flow of electrons passes through a material, it is referred to as current. There are two types of current, direct and alternating. Direct
To investigate the factors which effect the resistance of a metal wire.
TO INVESTIGATE THE FACTORS WHICH EFFECT THE RESISTANCE OF A METAL WIRE Aim: To find how different factors affect the resistance of a metal wire. Hypothesis: For this investigation I think that the thinner the wire the higher the resistance of the wire. This is because the electrons in the wire can flow more easily when the wire is thicker because there are less collisions and therefore less resistance so when the wire is therefore thinner there are more collisions and the electrons flow more slowly creating more resistance. Knowledge that I already have is Ohms law and how to measure resistance using a voltmeter and an ammeter. Ohm's law states that the amount of current flowing in a circuit made up of pure resistances is directly proportional to the electromotive force impressed on the circuit and inversely proportional to the total resistance of the circuit. The law is usually expressed by the formula I = E/R, where I is the current in amperes, E is the electromotive force in volts, and R is the resistance in ohms. This enables us to work out the resistance using the current and voltage. R=V/I. Theory: Atoms are made up of a positively charged nucleus surrounded by negatively charged electrons. In solids, one or two of the electrons in each atom are used to form the bonds between atoms that hold the solid together. In a metal these bonding electrons are free to move
"Are rechargeable batteries more economical than alkaline batteries?"
IB Extended Essay 07-05-2003 Candidate Name: Willy Gunawan Candidate Number: D0612-027 School: Wesley College, Melbourne School Number: 0612 Subject: Chemistry "Are rechargeable batteries more economical than alkaline batteries?" Words: 3711 Acknowledgements: 07/04/2003 I acknowledge that the work of others has been appropriately referenced and that all unacknowledged work is genuinely mine. Along with this I want to thanks all the support given by my family, and Ms. Karen Hamilton which has been very patient in guiding me and was a tremendous mental support and me during this hectic time of doing the assignment itself. Thank you, for making it possible for me to finish the project. As English is my second language, a lot of effort and time has been put into ensuring that my language is properly used, and make sense. Yet it is inevitable that I made linguistic mistakes along the way. I would like to use this opportunity, to apologise if that is the case. Willy Gunawan Contents: Title Page..............................................................................................1 Acknowledgements..................................................................................2 Table of Contents....................................................................................3 .
To investigate how the resistance, R, of a length of wire, l, changes with diameter, D and determine the resistivity of the material the wire used.
Resistance of a Wire Aim To investigate how the resistance, R, of a length of wire, l, changes with diameter, D and determine the resistivity ? of the material the wire used. Introduction In this experiment, I am investigating the resistance, length and diameter to find the resistivity of a wire. Hence, we use the resistance formula to calculate this: R is the resistance of the conductor in Ohms (?) A is the cross sectional area in m2 l is the length of the wire in metres (m) ? is the resistivity of the material in Ohm metres (?m) Three external factors influence the resistance in a conductor. Thickness (cross-sectional area of the wire), length, and temperature all have some effect on the amount of resistance created in a wire. The fourth factor is the resistivity of the material we are using. The wires which are available for use are: Constantan (mm) Nichrome (mm) Cross sectional area (x 10-8m2) 2.d.p 0.19 2.80 0.23 4.10 0.28 0.28 6.10 0.31 0.31 7.50 0.37 0.37 0.70 0.40 2.50 0.45 0.45 5.90 0.56 24.60 0.71 39.50 0.90 63.50 .25 22.20 I found that it would be better to use the constantan wire because of the range of diameters, hence a wide range of cross sectional areas of wire are available. The temperature coefficients of the resistance for a constantan and nichrome wire are shown in the table below: Substance Temperature
--- PHYSICS INVESTIGATION ---
--- PHYSICS INVESTIGATION --- FACTORS WHICH AFFECT THE RESTISTANCE OF A WIRE AIM: The aim of the investigation is to investigate the factors that affect the resistance of a wire. Resistance is affected by certain factors. The four main factors which affect resistance are: . Temperature 2. Length 3. Thickness 4. Materials. These must be kept constant throughout the experiment except the length of the wire. These CONTROLLED VARIABLES (except LENGTH) are as explained: . TEMPERATURE: affects resistance as when the temperature of a metal increases the resistance of the metal increases and the current decreases. The reason for this is because as the temperature increases the atoms of the metal tend to vibrate more vigoursly each time as of the increase in energy. This in turn makes it more difficult for the electrons to move across the wire as they collide with the atoms of the metal on the way to the positive end of the wire, therefore increasing the amount of collisions meaning there is/would be more resistance. However, keeping the temperature constant throughout the experiment could prove fairly difficult as the temperature could easily increase or decrease, unless you have the correct apparatus to keep the temperature constant or complete the experiment on the same day at room temperature. It is essential to use a low voltage as it will mean a low current which will
The Bouncing Ball Experiment
The Bouncing Ball Experiment A Ball Drops: Energy is needed to do everything. Light, sound, movement and heat are all examples of things that need energy to exist. Energy is defined as the ability to do work - to make something happen e.g. to move something. If something can apply a force over a distance, it has energy. The easiest way to detect energy is when it is changed from one form to another. To then measure how much energy is present, we can measure the amount of work done whilst the transformation is occurring. An object can store energy as a result of its position. When a ball is held at a height, it stores energy. This stored energy is referred to as potential energy. It is called potential energy because the ball has the potential to drop (converting the potential energy into kinetic/movement energy), if it is let go of. The higher the ball is from the ground, the more kinetic energy it will need to fall back down. The kinetic energy is converted from the Gravitational Potential Energy the ball has when it is elevated. Gravitational potential energy is the energy stored in an object as the result of its vertical position. The ball falls to the ground due to the force of gravity by converting the gravitational potential energy (GPE) into kinetic energy needed for the ball to move. The higher the ball is elevated, the more GPE it has. As the ball
Investigation into the factors affecting the resistance of wire
Investigation into the factors affecting the resistance of wire Part 1 (Basic investigation) Aim: The aim of this first experiment is to look into the factors affecting the resistance of a length of wire when a current is passed through it. Resistance is caused by electrons colliding with ions in the wire. When this happens energy is wasted because it is converted into heat and light etc. The less resistance there is the more useful the wire is as a component to transfer electricity, although obviously in some cases resistance is wanted in certain components such as heating elements. The factors I am going to focus on will be length, diameter and material of the wire, two properties that can be changed affecting any simple circuitry. Plan: This part of the investigation will involve collecting resistance readings firstly for varying lengths, then varying width, and finally varying metals. The majority of the experiment setup will be kept the same for these three tests and will be set up as shown in fig.1 The equipment list is as follows: DC power supply Leads Ammeter Voltmeter Crocodile clips Test wire: 6, 18, 26, 30, 36swg copper wire, 26swg constantan, 26swg manganin Meter rule With the equipment set up as shown I will first start by testing the resistance over different lengths of wire. Using the 36swg copper wire because it should be expected to have the
To investigate the factors affecting current in a wire.
To Investigate The Factors Affecting Current In A Wire Introduction The aim of this investigation is to find out the factors that affect current in a wire. Electric current is defined as the rate of flow of electric charge. Variables that may affect the resistance of the wire Every appliance has a resistance. If the resistance is high, the current will be low. If the resistance is low, the current will be high. The variables that can affect the resistance in a wire are: - Cross-sectional area of the wire - Length of the wire - Temperature - The material (resistivity) - Voltage Cross-Sectional Area The thicker the wire is, the lower the resistance, therefore the higher the current (given that all other factors are constant). When a wire is thick, there are more electrons available to carry the current. Free electrons are available in metal (wire), if the metal has a larger cross-sectional area - more electrons will be available. If the wire is thinner, fewer electrons will be available to carry the current. A thick wire has more free electrons and more space. A thin wire has less free electrons and is more 'squashed' together. This means that the electrons are likely to collide more with the metal ions in the wire. Collisions in a metal wire will result in an increase in resistance because the ions from the metal wire will be getting in the way of the flow of
To find a relationship between the molecular size of different alcohols and the associated energy change involved in the reaction.
Introduction The aim of the investigation was to find a relationship between the molecular size of different alcohols and the associated energy change involved in the reaction. A preliminary experiment had been carried out already and errors were noted accordingly and were adjusted in this experiment where possible. This investigation looked into the energy changes when different alcohols were combusted, this is the reaction of the alcohol with oxygen in the surrounding air. The alcohols are a homologous series of compounds that contain -OH as the functional group (a group of atoms in a structure that determines the characteristic reactions of a compound). For this experiment, only methanol, ethanol, propanol, butanol and pentanol will be used. Alcohol Molecular formula, CnH2n+1OH Boiling point (ºC) Methanol CH3OH 65 Ethanol C2H5OH 78 Propan-1-ol C3H7OH 97 Butan-1-ol C4H9OH 17 Pentan-1-ol C5H11OH 37 The structures of alcohols Here's where the alcohol structures go, sorry I couldn't send them! In general, alcohol + oxygen --> carbon dioxide + water E.g. ethanol + oxygen --> carbon dioxide + water C2H5OH(l) + 3O2(g) --> 2CO2(g) +3H2O(l) Hypothesis The larger the molecular size, i.e. the more carbon atoms it has, the larger the amount of energy given out. Some chemical reactions are capable of releasing a lot of energy; usually it is through
Physical - Circuit
P O A E 6 6 6 4 24/30 Name: Daniel Shih Class: F5D Teacher: Dr. Aravind School: Kiangsu-Chekiang College International Section Date: 30th November, 2006 Index Introduction Planning - Aims, Variables, Fair Test, Prediction, Hypothesis Planning - Apparatus, Procedure Planning -Procedure of temperature, measurement, safe rules Obtaining Analyse - Table 1 Analyse - Table 2 Analyse - Table 3 Analyse - Table 4 Analyse - Table 5 Analyse - Table 6 Analyse - Table 7 Analyse - Table 8 Analyse - Compare and Contrast Evaluation, Conclusion, Bibliography Introduction: What is an electrical circuit? An electrical network is an interconnection of electrical elements such as the resistors, inductors and switches. We use circuit to measure the voltage, and also the current of some conductors which can transfer the electricity. To design an electrical circuit, first we need to be able to predict the current and the voltage. What is electrical resistance? Electrical resistance is a measure of the voltage divided by the current flows in the electrical circuit. The unit of resistance Is Ohms,?. The quantity of resistance in an electric circuit determines the amount of current flowing in the circuit for any given voltage applied to the circuit. The way of measuring the resistance in a circuit is: "R" is the resistance of the object, measured in ohms. "V" is the
