What affects the current through a wire?
What affects the current through a wire? Planning Variables . Temperature: If the wire is heated up the atoms in the wire will start to vibrate because of their increase in energy. This causes more collisions between the electrons and the atoms as the atoms are moving into the path of the electrons. This increase in collisions means that there will be an increase in resistance, slowing the current down. 2. Material: The type of material will affect the amount of free electrons that are able to flow through the wire. The number of electrons depends on the amount of electrons in the outer energy shell of the atoms, so if there are more free electrons in the atoms then there must be more electrons available. If the material has a higher number of free electrons then the material has a lower resistance. Conversely if there are less free electrons then the resistance of the material is said to be higher. 3. Wire length: If the length of the wire is increased then the resistance will also increase as the electrons will have a longer distance to travel and so more collisions will occur. Due to this the length increase is directly proportional to the increase in resistance. 4. Wire diameter: If the wires diameter is increased the resistance will decrease. This is because of the increase in the number of free electrons available in the larger volume of the same material. Due to
Investigate how the resistance of the wire changes as the length of the wire changes.
Physics Coursework Aim: To investigate how the resistance of the wire changes as the length of the wire changes Background information: Some information that I must take into account is: That the resistance of a wire is . Directly proportional to its length 2. Inversely proportional to its cross section area I can use Ohms law in my experiment to calculate the resistance. Ohms Law = V =IR Voltage = Current Resistance This can be rearranged to give me the resistance to R = VI Resistance = Voltage Current Prediction: I predict that if the length increases then the resistance will also increase in proportion to the length. I think this because the longer the wire the more atoms and so the more likely the electrons are going to collide with the atoms. So if the length is doubled the resistance should also double. This is because if the length is doubled the number of atoms will also double resulting in twice the number of collisions slowing the electrons down and increasing the resistance. My graph should show that the length is proportional to the resistance. Plan: There are some variables that would affect the resistance of the wire, they are . The temperature 2. The length 3. The thickness of the wire 4. The material of the wire I will be keeping constant the temperature, the thickness, and the material. I will change the length of the wire and
An investigation into the effects of differing diameters of wire on current through the wire.
An investigation into the effects of differing diameters of wire on current through the wire. Planning In this investigation, we will try to find out if there is a relationship between the diameter of a wire in a circuit and the current through it at differing voltages. Apparatus Power Pack Wires Crocodile Clips Bare Wire of differing diameters Voltmeter Ammeter Wire Cutters Metre Ruler Micrometer Procedure Pick several wires that give a good range of diameters, such as: 20s.w.g., 24s.w.g., 32s.w.g., 36s.w.g., and 38s.w.g.. Measure out and cut 50 cm of each wire, labelling each so that we can easily tell the difference. Measure each wire using the micrometer, and repeat this in at least three different places in the wire. Note all these measurements and record the average as well. Connect up the apparatus into the circuit as shown above, and turn on the power pack. Change the voltage to 0.5V, according to the voltmeter, and read the ammeter reading, and record it neatly. Change the voltage, and then return it to 0.5V, and read off the ammeter. Record this and the average. Then increase the potential difference to 1.0V and repeat the procedure. Repeat this with each wire at voltages of 0.5V, 1.0V, 1.5V, and 2.0V. If there is a case where the ammeter reading exceeds 4A, take the highest possible voltage reading, as there is a 4A limiter on the power pack. In order
We are going to set up the diagram above and measure the resistance across the wire by measuring the current and voltage then working out the resistance using R=V/I.
Wires Coursework for GCSE. Area P-Planning We are going to set up the diagram above and measure the resistance across the wire by measuring the current and voltage then working out the resistance using R=V/I. The variables that will change are the resistance setting on the protective resistor and the cross sectional area of the wire-we will change the thickness of the wire and see how the resistance is affected. When the protective resistance is changed the current and voltage will change but the resistance should remain the same. The thicker the wire, the less resistance. I think the things that might affect the resistance of the wire are the area, the number of items (eg bulbs), the brightness or power needed to operate the item, whether it is in a series circuit or parallel circuit, the current and the power supply. We calculate resistance using the formula R=V/I, where R=resistance, V=voltage and I=current. Voltage divided by current gives us the resistance, as voltage is the number of volts wanting to pass through the wire, whilst the current tells us how many are passing through at that point. To change the wire diameter, we will use different wires. There are 8 wires we are going to use and they have diameters of: 0.315 0.559 0.376 0.234 0.712 0.193 0.457 0.274 During our experiments, we will note down specific details. We will take readings of the
To investigate the affect of wire width on electric current and resistance.
COURSE WORK PIECE 1: RESISTANCE HARRY HUDSON 10U 25/5/02 AIM: To investigate the affect of wire width on electric current and resistance. INTRODUCTION: What is electricity? Electricity is the phenomena resulting from the existence of charge. The units of charge are: one electron (negative charge) and one proton (positive charge). All normal atoms contain both of these particles, as well as neutrons (neutral charge). All solid metals contain atoms arranged in a regular structure. One or two electrons per atom are weakly attracted as they are further from the nucleus and are held in by a weaker force, and thus may move away from the atom and "wander" through the metal. The loss, or gain moveable electrons means the material has positive or negative charge. The main units used to measure electrical quantity are: ampere (unit of current), the coulomb (unit of charge), and the volt (measurement of electromotive force). What is current? Current is the term used to denote a flow of electric charge. This is known as ELECTRODYNAMICS, as we witness charge in motion. Electrons may flow through any material known as a conductor (all metals). The reason for this is the `free' electrons moving within the metals structure. In order for current to exist in a conductor, there must be an electromotive force (emf), or potential difference in charge at the two ends of
Investigating resistance of resistors in series - What effect, if any, does the length of a wire, have on its resistance?
Pilot Study: Investigating Resistance of Resistors in Series Circuit A Circuit B Method Set up Circuit A according to the diagram. Set the power pack to a low voltage: it should give a low current around 0.20 A. this is because a high current would cause a resistor to get hot and this will affect the resistance. Switch on the power pack and record values for the V (voltage) and I (current). Repeat this twice to ensure the experiment is reliable. Calculate resistance using Ohm's Law (R= V/I). Repeat the procedure for Circuit B. Results Circuit A V (V) I (A) Resistance (?) .35 0.26 6.2 .41 0.28 5.04 .39 0.27 5.15 Average Resistance is 5.13 ? Circuit B V (V) I (A) Resistance (?) .70 0.14 2.14 .63 0.15 0.90 .60 0.15 0.70 Average Resistance is 11.33 ? Conclusion Using two identical resistors in series gives double the resistance of one. We can see this from the results that show Circuit B to have double the resistance of Circuit A. Each resistor is made of a fixed (a certain) length of wire, and if we double the number of resistors, it means doubling the length of wire. This doubles the resistance. This suggests the longer the wire, the higher the resistance. Skill Area P: Planning What effect, if any, does the length of a wire, have on its resistance? Aim The purpose of this investigation is to see how the length of wire
Investigate how the resistance of wire changes as the length (and width) increases.
Investigate how the resistance of wire changes as the length (and width) increases Planning Aim: I am going to investigate how the resistance of wire changes, when the length (and width) increases. Variables: Justification: I have chosen to change the length of wire because: * It is easy to get accurate results * It is easy to get multiple results * I can get a varied range of results All of these should outcome in getting a good graph. Prediction: I predict that as the length of the wire increases the resistance will escalate. I predict this because the longer the wire is the further the electrons have to move to go through the length of wire. Therefore, there is more of a chance of them crashing into the metal atoms making more resistance. For example if the wire is 10cm in length, there is not as many atoms for the electrons to travel through, which means less collisions, amounting to less resistance. But if there is 50cm of wire there is a lot more atoms for the electrons to travel through, causing more collisions equalling more resistance. I also think that it will be the same with a thicker width of wire. Circuit diagram: KEY Power Pack Wires Ammeter Voltmeter Thin Wire Variable Resistance Metre rule Crocodile Clips Wire one Wire two Equipment: 6V Power Pack 8 wires Ammeter* Voltmeter* Variable Resister Thin Wire (+ Thick wire) Metre
Resistance in a Wire Investigation
Introduction : Resistance is a force which opposes the flow of an electric current around a circuit so that energy is required to push the charged particles around the circuit. The circuit itself can resist the flow of particles if the wires are either very thin or very long. e.g. The filament across an electric bulb is quite thin as needs to resist the flow of particles for the bulb to glow. Resistance is measured in ohms. George Ohm discovered that the emf of a circuit is directly proportional to the current flowing through the circuit. This means that if you triple one, you triple the other. He also discovered that a circuit sometimes resists the flow of electricity. He called this resistance. He then came up with a rule for working out the resistance of a circuit : V/I = R V - Volts I - Current R - Resistance. Extra Background Information : The total resistance of resistors in series is the sum of the resistance of each one. Each cm of wire has a particular resistance, if you double the length of wire, it is like having two of the shorter wires in series. If the small resistor represents a short wire and the large resistor is a long wire of double the length of a short one. One short wire has a resistance of 1ohm, 2 short wires have a resistance of 2ohms when connected in series. The long wire is just like two short wires put together. Aim : To
Investigation into the resistant in wires.
Physics SC1 Oliver lamb Investigation into the resistant in wires Aim: to investigate how the length of a wire affects the resistance. Apparatus: Wire (SWG 25) Ammeter Power source 4v Crocodile clip Variable resister Meter ruler Voltmeter Leads Method: Set up the apparatus as shown in the circuit diagram below. The length of the wire is changed between 0cm and 100cm at 5cm intervals. The current needs to be kept at a constant of 0.3 amps throughout the experiment and the voltage across the wire at each length of wire is recorded. The experiment is repeated 3 times with each length of wire, and an average obtained. If any obvious anomalies occur, then these are repeated also. Prediction: I predict that the longer the wire, then the greater the resistance. Conductivity of a metal depends on the numbers of free electrons, which are contained within it. The more free electrons, the more conductive the metal is, as the free electrons are given energy and then collide with neighbouring free electrons. This happens throughout the wire and electricity is conducted. Resistance is a result of energy lost as heat, and is measured of how much is lost in this way. Free electrons colliding with fixed particles within the metal, other free electrons and impurities cause the loss of energy. These collisions convert's some of the energy that is carried by free electrons into
GCSE Physics Coursework - Current in a Wire
GCSE Physics Coursework - Current in a Wire Coursework Variables to be measured: * Length of Wire * will be varied * Material of wire (experiment will be repeated for wires of different materials to see if the same effects are present when the length is varied) * Current through piece of wire. * Voltage across piece of wire. Variables to be kept constant: * Starting Temperature of the wire * Width of Wire (Cross-sectional area of wire) - for each experiment, the width of wire will not be varied. * Voltage supply from power pack (6 volts). Theory Current is directly proportional to voltage. The current is also dependent on resistance: if the resistance is increased in a circuit, the more voltage is required to push a certain amount of current through a component (I = V/R). The more resistance, the more the voltage is divided by, and the less the current will be. As Resistance is the opposite to current, and both depend on how free electrons will move, factors affecting resistance will also affect Current. Ohm's Law: "The current through a wire remains the same provided the temperature remains constant." Proposed Method As previously discussed, the length of wire was the easiest to control and measure, so this is what I shall vary. The following circuit was made to carry out the investigation: . One metre length of a wire is fixed to a metre rule. 2. The
