What factors affect the resistance of Ni-Chrome wire?
What factors affect the resistance of Ni-Chrome wire? Hypothesis I am investigating what affects the resistance of Ni-Chrome wire. The main variables I could test are the thickness of the wire, the length of the wire and the temperature of the wire. I am going to investigate how the length of wire affects the resistance of Ni-Chrome wire. What is Ni-Chrome wire? Ni-Chrome wire (NiCr60) is a Nickel and Chrome Alloy it consists of the following elements nickel: 57-58%, chromium: 16%, silicon: 1.5%, iron: Balance. Ni-Chrome wire is commonly used as a resistance heater for cutting foam (Styrofoam, polyurethane, etc.) fabrics, and a variety of other materials. What is resistance? Resistance is the electrical term used to describe the property that various materials have to restrict or slow down the flow of electricity or current. Electrical resistance is low in most metals and high in most non-metallic materials. Electrical resistance is measured in ohms (?). I am going to use this formula calculated by George Ohm to calculate resistance. Voltage / Current = Resistance V V / I = ? I R Diagram to show the movement of electrons through a wire I predict that the longer the length of wire the more resistance will occur. This is because the longer the wire the more atoms present consequently this increase the amount of times that the electrons
Factors Affecting The Resistance Of A Metal Wire.
Helen Roberts 10P March 2003 Physics AT1 PLANNING Factors Affecting The Resistance Of A Metal Wire . Investigate some of the factors that affect the resistance of a metal wire. The current and voltage will be measured and then V = IR will be used to calculate the resistance. The potential divider circuit produced better results in the investigation into how resistance depends on the number of identical resistors connected in series, so this circuit will be used for this investigation, too. Variables and Constants 2. Possible variables include the length of the wire, the diameter of the wire, the material of the wire and the temperature. The chosen variable is length of the wire. Because this is the chosen variable, all of the others must be kept constant. The graph I will plot will be the length of the wire (in cm) against the resistance (in ?). Trials 3. Trial using a short length and a long length (10cm and 60cm) of each of the three types of wire. The three types of wire are as follows, copper 0.274mm, nichrome 0.274mm and nichrome 0.457mm. The voltage and current will be measured and the resistance calculated (using V = IR). The wire that has the largest variation between the two measurements will be used, to provide the best results possible. Preliminary Work 4. Copper wire - 0.247mm diameter Length Current (A) Voltage (V) Resistance (?)
resistance of a wire
Aim The aim of this coursework is to investigate how the length of a constantan (18SWG) wire affects the resistance in a circuit. Preliminary Testing Before I can conduct the experiment I need to investigate further into what I am going to do for the investigation. By doing the preliminary testing I can find the easiest and the best method of doing the experiment. I can also make any alterations to the investigation. The first problem I had was the material that I was going to use as a conductor. I decided to choose constantan wire because it is cheap and it is easily found. Another reason for choosing this was because the resistivity was not that small or large to work with. The table below shows the possible materials we could have used. Material Resistivity/m Silver Copper Aluminium Iron Constantan Mercury Germanium Alumina Pyrex Fused Quartz The next decision I had to make was the type of constantan wire we could have used. I chose to use 18 SWG because its diameter was not to small and not to large. I had other alternatives as well the table below shows this. S.W.G 6 8 20 22 24 26 28 30 32 34 36 38 40 Diameter (mm) .62 .25 0.91 0.71 0.56 0.46 0.38 0.32 0.27 0.23 0.19 0.15 0.12 Now that I have decided on my apparatus I now need to work on the factors. There are many factors that could be taken in to account. I
Resistance of a Wire
Background scientific knowledge Electricity Electricity is the movement of charge (electrons) around a circuit. The charge flows throw conductors which allow the electrons to pass through. An object which does not allow electrons to pass through is an insulator. Conductors intended to have resistance are called resistors (symbol ) Voltage- given the symbol V, measured in volts using a voltmeter Current- given the symbol I, measured in Amperes using an ammeter Metallic structure diagram Resistance Resistance is the ability to prevent or resist the flow of electrical current. Resistance occurs in an electrical circuit because of a collision between electrons and atoms, which slows the electrons down and converts some of their KE to heat energy. Resistance is measured in Ohms (?). Diagram Arrow shows direction of electron movement through the wire. Equation Factors which affect resistance Length of wire - this is being investigated Thickness of a wire - in a thin wire there are more possible paths for the electrons to pass through, therefore more electrons can flow through at one time, this increases the current which increases the resistance. Material of wire - wires of different densities will block more or less electrons Temperature - the vibration of warm molecules makes them more likely to collide with electrons, and resistance
Resistance of a Wire
Will changing the length and type of wire affect the resistance? What is my aim of this project: To set up an electric circuit to measure the resistance of the wire. What are my Variables: * Thickness of the wire * Length of the wire * Type of wire Equipment I plan to use: * Wires * Volt meter * Ammeter * Crocodile clips * Power pack * Ruler * Copper coil * Nichrome coil What is resistance? Resistance is measured in (OHMS). It is the hindrance to the flow of charge. Why did we get resistance? An electric current flows when electrons move through a conductor. The electrons that are moving can collide with the atoms of the conductor. This then means that it is more difficult for the current to flow, which causes resistance. On the other hand, electrons have a collision with atoms more often in a longer wire than they do in a short one, however, a thin wire has fewer electrons to carry the current than a thick wire. In a thin wire there is less space, but more resistance and in a long wire there is more space, yet less resistance. The flow of electrons: Hypothesis: Before I do my experiment I predict that the resistance in the wire will increase as the length of the wire increases. I also predict that if the resistance in the wire increases, then the thickness of the wire will decrease. My diagram of my circuit: For my first investigation task I will be
Resistance of a Wire
Resistance of a Wire Coursework Planing (Final) Independent variable: -Length of wire (cm) Dependent variable; -Dial voltage (4 volts) -Material of wire (Nickel chrome) -Width of wire (28 SWG) Aim: My aim is to see how the length of the wire affects the resistance. Prediction & Hypothesis: My prediction is that when the length of wire increases, the resistance will also increase. Same as when the length of the wire doubles, the resistance will also doubles because Resistance is caused when the electrons collide with the ions. Therefore when it is doubled, the electrons will collide with twice as many ions, so the resistance will also double. Introduction: Measuring equipments I have chosen a digital voltmeter and an ammeter as my measuring equipments because it shows the voltage and current in decimal points, so I know that my results can be more accurate. Range and intervals My length of wire will increase 10 cm every time and I will make 6 readings. I will repeat all my reading twice and get the average to make sure that they are the most accurate results that I can get. Results Plan The heading for my results table will be 'dial voltage', 'actual voltage', 'length of wire', 'current', and 'resistance'. To ensure a fair test I will make sure that the dependent variable will be the same through out the experiment. Safety I will assure that when I conduct
Resistance of a wire
INTRODUCTION - An electrical circuit was mounted using a power supply, an ammeter, a voltmeter and a resistor (wire). The voltage and current were worked out for different lengths of the wire using the ammeter (for the current) and the voltmeter (for the voltage). Using the voltage and current recordings, the resistances were calculated for each of the lengths. AIM - To investigate the correlation between the length and the resistance of a wire. DIAGRAM - PICTURE - HYPOTHESIS - I predict that the longer the wire, the greater the resistance. This is because the electrons have to move in a longer distance, making the opposition (resistance) of conductor to the current greater. RESULTS - Tables of results to show the resistance of the wire for different lengths. TRIAL 1 Length (cm) Voltage (V) Current (A) Resistance (?) 00 6,4 7,2 0,888888889 90 6,3 7,7 0,818181818 80 6,2 8,7 0,712643678 70 6,3 0,2 0,617647059 60 6,1 1,5 0,530434783 50 6,1 3,7 0,445255474 40 6,15 6,8 0,366071429 30 5,83 21,8 0,267431193 20 5,71 29,3 0,194880546 TRIAL 2 Length (cm) Voltage (V) Current (A) Resistance (?) 00 6,4 7,3 0,876712329 90 6,4 8,1 0,790123457 80 6,67 9 0,741111111 70 6,28 9,9 0,634343434 60 6,32 1,9 0,531092437 50 6,28 4,2 0,442253521 40 6,12 7,3 0,353757225 30 6,09 22,4 0,271875 20 5,9 32,9
