Nuclear Power
The benefits and drawbacks of Nuclear Power Nuclear Power is power that is generated by a controlled chain-reaction from nuclear fission in which a uranium-235 atom splits up into two daughter nuclei (Krypton-91 and Barium-143); the uranium also releases three neutrons when it splits. In nuclear reactors these neutrons are controlled by boron control rods so that only one neutron can get through to the next enriched uranium rod and initiate further nuclear fission, this process is called a chain reaction. In a nuclear power plant the vast amount of heat energy that is released from a chain reaction is carried to the heat exchanger, where the heat will be transferred into a water pipe, turning the water into steam (there are variations but the diagram above shows the major system). As in coal powered power stations this steam is then used to turn a turbine which in turn will turn a generator so an electrical current can be induced. Currently in the UK there are only 19 operational nuclear reactors generating 11852 megawatts of electricity, however the government wants to expand the UK's nuclear program so they can meet the targets set by the Kyoto Protocol of reducing the carbon emissions to 40% by 2050, nevertheless people are unsure about the environmental and social impacts of nuclear power. This report will explain the benefits and drawbacks of nuclear power using the
Nuclear Power
Nuclear Power Nuclear power plants create electricity using the energy released by splitting atoms to boil water and create steam which turns a steam turbine driving a generator. Since no fuel is burned, there are no gases or pollutants released into the air. The water used to create steam is isolated from radiation and any hot water to be discharged is cooled down in ponds or in tall cooling towers. Nuclear waste is the only byproduct of nuclear power and is packaged and stored rather than released into the environment. Unlike other fossil fuels, nuclear power plants release almost no emissions into the environment. Two different light-water reactor designs are currently in use, the Pressurised Water Reactor (PWR) and the Boiling Water Reactor (BWR). Diagram of a PWR In a PWR, the heat is removed from the reactor by water flowing in a closed pressurized loop. The heat is transferred to a second water loop through a heat exchanger. The second loop is kept at a lower pressure, allowing the water to boil and create steam, which is used to turn the turbine-generator and produce electricity. Afterward, the steam is condensed into water and returned to the heat exchanger. Diagram of a BWR In a BWR, water boils inside the reactor itself, and the steam goes directly to the turbine-generator to produce electricity. Here, too, the steam is condensed and reused. How a
Ohm's law.
Background Information, Introduction Ohm's law what is it about? "Ohm's Law states that the current through a metallic conductor at constant temperature is proportional to the potential difference. (p.d.). Thus p.d. over current is constant." GCSE Text Book. What is resistance? Resistance is defined as voltage over current. The unit of resistance is the ohm (?). So; Resistance = Background Information (Found in "Google.com") Electricity in wired circuits consists of the flow of electrons. Current is the word used to describe this flow, and is measured in amperes. Because positive and negative charge "dislike" being apart, current can only flow when a complete circuit exists: At least one closed loop for the electrons to run around. Current flows because of an electric potential-voltage-that exists in the circuit. An example of a source of voltage is a battery; here electrochemical reactions produce electric potential. Another example is a power generator powered by steam (a turbine) or by rushing water (hydroelectric generators). The former are examples of constant (DC) voltage sources (most flashlight batteries produce a constant 1.5 volts) and the latter AC sources, where the voltage varies in a pattern like that of a sinus curve. Circuits are comprised of the interconnection of circuit elements. Each element is distinguished by the relation it imposes
Ohm's Law Investigation
Safety -Follow basic lab rules -Don't overheat nicrome wire, use very low current to prevent wire breaking -Place all schoolbags under tables -Place stools under table Background Knowledge The flow of electricity along a wire is similar to the flow of water along a pipe. For more water to flow down the pipe, you have to push the water harder by turning the tap. This is the same in electric circuits. More current flows along a wire when the EMF pushing the electrons is greater. Ohm's law describes how the current and the voltage flowing a wire are related. Electrical resistance is a property of all materials. It measures how much the material inhibits the flow of electrons. High resistance allows a small amount of current to flow. This resistance is measured in ohms ( ). Nicrome wire opposes the flow of current more than copper, therefore nicrome has a higher resistance than copper. Non-metals insulate electricity, therefore they have a high resistance, whereas metals conduct electricity so they have a low resistance. The resistance of a wire increases with length, decreases if the cross section is increased, and also depends on the type of material. George ohm :Was German school teacher :Was born in 1787-died in 1854 :From 1852 until his death he was a professor of experimental physics. :The first scientist to discover the relationship that the current
Ohms Law.
Ohms Law Aims and hypotheses This investigation is designed to look into the resistance of different material in the form of wires and their conducting capability in different shapes. In order to do so, the materials are to be tested for their resistance in the shape of wires, and the hypotheses are such that different thickness and length of the wire and the material that makes up the wire itself will affect the electric conduction capability. Hence, the factors are: * The thickness of the wires: 1, 2 , 3and 4 mm in diameter * The length of the wires: 25, 50 , 75and 100 cm long * The material of the wires: copper, iron, constantan and nichrome * There will be 16 tests to be carried out The experiment will require both the readings of voltage and current in order to produce the value of resistance according to the formula: R = V/I ?? (Resistance is measured in Ohms) The power supply, however, is varied between 0-12V with 1V interval so that a series of results can be obtained with the single factor altered: a graph of V against I can be drawn and an average resistance can be produced in this case, rendering it a fairer test. Since each test does not take long, the tests can also be repeated to obtain a more accurate mean. DC supply is used so that the voltage and current are not fluctuating while a steady reading is needed to be obtained. To make it a fair test,
Electrolysis COursework
Electrolysis Coursework Aim: To investigate whether increasing the voltage through a copper sulphate solution increases the amount of copper extracted. Introduction: Electrolysis is the process in which an electric current flowing through a water solution of a chemical breaks that compound up into its component parts. I will be investigating how changing the voltage through an ionic copper sulphate solution, increases the amount of copper extracted on to the anode. I will do this by varying the voltage to calculate the effects of this factor on the original mass and solution mass after. From this I will calculate the difference, so it is easy to compare and evaluate. Apparatus: - Power Supply Unit (PSU) - Top Pan Balance - Wires - Electrodes - Anode - Electrode holder - 20cm³ CuSO4 solution - Small Beaker - Measuring Cylinder Prediction: I predict that the higher the voltage the higher the amount of copper on the cathode. In the same way, I also predict that the lower the voltage the lower the amount of copper on the cathode. Hypothesis: I base my prediction on my belief that when the voltage is low, the current is weak and therefore less can be separated. In the same way I believe that when the voltage is high, the current is strong so more of the solution can be separated. In electricity opposites attract. Therefore the metals ions, that are positively
Electrolysis Investigation
Planning I did some preliminary work to see which current values, and for how long to time. The results of this are in the tables below: Electrode-1A Mass before (g) Mass after (g) Mass change (g) Anode 1.38 1.30 -0.08 Cathode 1.35 1.65 +0.30This was done for 10 minutes. The mass lost at the anode should equal the mass gained at the cathode, which this doesn't, it has a percentage inaccuracy of 0.22¸ .30x100= 73% which is very inaccurate, This may be due to the current being too high, so the copper does not all transfer properly, but lies on the bottom of the beaker, therefore a lower current must be used, as in the table below: Electrode-0.1A Mass before (g) Mass after (g) Mass change (g) Anode 1.42 1.35 -0.07 Cathode 1.16 1.21 +0.05This was also one for ten minutes, and shows much more accurate results, as the percentage inaccuracy is only 0.02¸ 0.07x100=29%, which is still inaccurate, but is a lot better . This could be due to the current value being to low, so I will take a range of 5 results from 0.1Amp to 1Amp at 0.2Amp intervals. Each electrolysis will last 10 minutes, and each will be repeated twice so that a more accurate average can be taken. Variables * Temperature of the electrolyte * The concentration of the electrolyte * The separation of he electrodes * The
Electrolysis Investigation
AIMS It is known that by passing a constant electric current through an aqueous copper sulphate solution that the passage of ions through this solution results in copper atoms being dissolved into the solution from the anode while positive copper ions (cations) being discharged at the cathode. Normally anions are discharged at the anode. The experiment carried out aimed to monitor the quantity of Copper (Cu) metal deposited during the electrolysis of Copper Sulphate solution (CuSo4) using Copper electrodes, when certain variables were changed. It was considered that the following factors could affect the deposition of Copper metal on the cathode. . Time 2. Current 3. Temperature 4. Molarity/Concentration of Solution 5. Quantity of Solution 6. Size of Electrodes 7. Distance between the electrodes 8. The surface of the electrodes The time was chosen because it is an easy quantity to measure and record, whilst at the same time maintaining the other variables at a constant level. The other factors could be observed in later experiments, should time allow. PREDICTIONS It is possible to predict that the relationship will be directly proportional between the time the current flows and the mass of Copper deposited on the Cathode (negative electrode). I can therefore predict that if I double the time of the experiment, I will therefore be
Electrolysis Investigation
PHYSICS COURSEWORK. Prediction. Electrolysis is the method of using electricity to separate two solutions. This works by passing electricity through the anode, (the positive electrode,) through the solution and then back up the cathode, the negative electrode. In this investigation we will be using Sodium Chloride (commonly know as salt) to react. If the ions are positively charged then they will be attracted to the cathode, the negative electrode, and if they are negatively charged then they will be attracted to the positive electrode, the anode. When we use the Sodium Chloride then the sodium ions will be attracted to the negative electrode and the chlorine ions will be attracted to the positive electrode. If we increase the concentration then the reaction will happen faster because there are more electrons and so the chance of a reaction happening is increased. The current is the flow of Ions in the electrolyte cell, so more Ions means more current. Variables. { [image001.gif] Material of the electrode. { Concentration. { Voltage. { Temperature. Independent { Surface area of the electrodes. Variables. { Distance between the electrodes. { Current. - Dependent variable. Apparatus. { Goggles. { Electrolysis Cell. { 6-Volt Power Pack. { Distilled Water. { Sodium Chloride. { Measuring Cylinder. {
Electrolysis of Sodium Chloride - NaCl.
Electrolysis of Sodium Chloride - NaCl Plan Aim I aim to find out how the concentration of Sodium Chloride (NaCl) affects the current. Hypothesis Electrolysis is the decomposition of a substance or compound with the use of electricity. Electricity is the free-flow of electrons (or charged particles). An electrical current is only able to pass through a substance if the electrons (or charged particles) are able to move. Graphite's electrons are free to move, hence it is a conductor of electricity. Ions enable charges to move freely in solutions, and therefore also are conductors. There are two graphite electrodes; the negative electrode - the cathode, and the positive electrode - the anode. In this experiment the ions present are; NaCl = Na+, Cl¯ H2O = OH¯ and H+. Therefore; At the cathode; Na+, H+ The most reactive out of these remains in the solution ; 2 H+ +2e¯= H2 (g) Here, we experience a gain of electrons, called a reduction At the anode; Cl¯, OH¯ If a halogen is present, halogen gas given off - Cl2 Here, we experience a loss of electrons, called an oxidation Left in the solution; Na+, OH¯ Prediction I predict that as the concentration of Sodium Chloride (NaCl) is increased, the current will increase also. I think this because the current and concentration are proportional; electricity is the free-flow of electrons (or charged
