Investigation of the resistance of a wire Essay Example

Investigation of the resistance of a wire Essay To investigate what affects the resistance of a wire.VARIABLES:The material of the wire e.g. iron has greater resistance than copper.The length of the wire.The cross-sectional area of the wire e.g. the width of the wire.The temperature of the wire.PREDICTION:I have chosen to base my investigation on the length of the wire. I predict that as the length increases, the resistance increases too.HYPOTHESIS:I hypothesise that the length of the wire affects its resistance. This is because from in-depth research from encyclopaedias and the internet I have found out that the electric current is the flow of charged particles around a circuit of conducting material. In solid metal conductors, current is a flow of negatively charged electrons; in an electrolyte it is a flow of positive and negative ions.The energy given to electrons to push them around an electric circuit is transferred from an electrical source, such as a power supply, a battery, solar cells or a generator, to components in t he circuit, such as resistors, lamps bells, LEDs and buzzers; the energy transferred makes things happen in the circuit, e.g. light, heat, sound.In an electrical circuit, the cell or the battery provides the electrons with electrical potential energy. It turns chemical energy from the materials in the cell into electrical energy in the electrons. The electrons move through the circuit from the negative terminal where they have high electrical potential energy towards the positive terminal. When the electrons reach a bulb (for example), they loose some of their electrical potential energy. This lost energy is turned into heat and light. Finally, the electrons return to the positive terminal of the cell with less energy. Therefore, there is a difference in electrical potential energy between the negative and positive terminals of the cell.The size of the current in a circuit depends on the voltage of the supply and on the resistance of the components: the current will change due to a result of a change in resistance. The resistance (measured in ohms = ?) is opposition to the flow of an electric current: the greater the resistance in a circuit, the more energy is needed to push charged particles around the circuit. For example, in the filament of a light bulb, the long, thin wire resists the flow of electrons so electrical energy is dissipated as heat and light.As the electrons in an electrical current move around a circuit, they bump into the atoms in the wires through which they pass. In my case, the longer the wire of an electrical circuit, the greater collisions into atoms, therefore, there is higher resistance.Here is a model illustrating resistance in a metal:The Ohms Law states that the current passing through a wire (or resistor) at constant temperature is proportional to the potential difference, a high resistance wire passes a small current and a low resistance passes a large current.METHOD:Fair testing:In this experiment I will only change 1 factor, wh ich is the length of the wire. The following factors that are going to be kept constant are:The room temperature since if the temperature is increased the particles in the wire will move faster and this would not allow the experiment to be fair.The cross-sectional area of the wire the thicker the wire, the less resistance. Thus, this would affect the resistance and the experiment would be unfair.The material of the wire this, as well, would affect the resistance because different materials have different conductivity, like I said earlier.The potential difference or voltage if this is changed, the temperature of the wire would also change therefore making the test unfair.Equipment:Nichrome wire, over 50cm long.A variable DC power pack.ResistorTwo crocodile clipsA 50cm ruler0 1 volts voltmeter0 1 amps ammeterconnecting wiresDiagram:Safety:Although this experiment is not very dangerous I still need to be cautious. I have to check if there are any breakages in the insulation of th e circuit wire, I must keep the current low, handle with dry hands to prevent electrical shocks.Procedure:Firstly, I will connect the circuit as shown above.Adjust the resistor until ammeter reads ___Record voltage shown on voltmeterThen, repeat the experiment with the following lengths of wire (cm):5, 10, 15, 20, 25, 30, 35, 40, 45.5. After that, I will use Ohms Law to calculate the resistance:Table: This is how my table should look like:Length (cm)Volts (V)Amps (A)ResistanceAverage Resistance1st 2nd 3rd1st 2nd 3rd1st 2nd 3rd51015202530354045Accuracy and Range of Readings:To make this experiment as accurate as possible I need to make sure that the length of the wire is measured precisely and make sure the wire is as straight as possible whilst I do this. I need to also ensure that the wire is straight while I do the experiment since this will affect the resistance leaving anomalous results. The readings of the voltage and current should be taken immediately after the circuit is con nected because as soon as the current is put through the wire it will get hotter and we only want to test it when heat is affecting the wire the least, at the beginning.To make my experiment as reliable as possible I will repeat it 3 times and then find an average result using the arithmetic mean.Arithmetic Mean = ? xnWhere:? is a capital Greek letter (sigma). ?x means the sum of all the terms and n is the number of terms.I will use this formula to calculate my Average Resistance and for the mean of graph (this allows me to work out the exact point where the line of best fit runs straight through).Graph Line of Best Fit:To calculate the line of best fit we need to use the formula:Y = mx + cWhere:Y is the y-axis, m is the gradient (y/x), x is the x-axis, and c is the y-intercept.Here are examples of 3 main types of correlation:RESULTS: Width of Wire: 0.55mmLength (cm)Volts (V)Amps (A)ResistanceAverage Resistance1st 2nd 3rd1st 2nd 3rd1st 2nd 3rd50.60 0.64 0.620.20 0.20 0.200.33 0.31 0.320.32100.54 0.56 0.550.25 0.30 0.300.46 0.54 0.550.52150.51 0.52 0.540.30 0.35 0.400.59 0.67 0.740.67200.46 0.48 0.470.40 0.40 0.400.87 0.83 0.850.85250.44 0.42 0.430.45 0.45 0.451.02 1.07 1.051.05300.40 0.40 0.420.50 0.50 0.501.25 1.25 1.191.23350.38 0.38 0.400.53 0.50 0.501.45 1.32 1.251.34400.35 0.34 0.370.60 0.60 0.601.71 1.76 1.621.7450.33 0.35 0.340.60 0.60 0.601.82 1.71 1.761.76*I have rounded my results to 2 decimal places to allow them become as accurate as possible.GRAPH:Y = mx + cY = mx + 0.13Y = (y/x) + 0.13Y = (1.47/40) + 0.13Y = 0.037x + 0.13Real life: for 0.55mm of nichrome wireAverage Resistance (ohms) = 0.037 x Length (cm) + 0.13Check:Lets assume that the Length (cm) is 10cm, what would the Average Resistance equal to?Y = 0.037 x 10 + 0.13Y = 0.37 + 0.13Y = 0.5this proves that my formula was accurate.MEAN OF GRAPH:Length (cm)Average Resistance50.32100.52150.67200.85251.05301.23351.34401.7451.76251.05MEANMean of Length = Total Length = 225 = 25No. of Readings 9Me an of Average Resistance = Total Average Resistance = 9.44 = 1.05No. of Readings 9Mean of Graph = (Mean Length, Mean Average Resistance)CONCLUSION:From my investigation I have found out that the resistance of a wire does change in proportion to its length. This is because as the length of the wire increased, the electrons increased as well, therefore there were more collisions which meant higher resistance. I knew, from the start of this experiment, that my results would lie on a positive correlated trend as I portrayed in my prediction. Because of thorough research, I found all the information that explained the relationship between the resistance and the length; this is why my results agreed with my hypothesis.EVALUATION:I believe that my results, in general, were reasonably accurate. However, I knew that if I used a voltmeter and an ammeter which was digitally calculated, instead of an analogue one, I suppose that my results would have been far more accurate than the ones I have. Nevertheless, my results on the graph lied on a straight line with two slight anomalies: (35,1.34) and (40, 1.7).I believe that this happened since the nichrome wire wasnt completely straight or it might not have been the same thickness throughout the length and this could have been the reason why the results werent consistent as it would have been. The crocodile clips were not always fixed securely to the wire with a good connection. This also meant that they were easy to move about on the wire, changing the length of it.I also believe that the crocodile clips could have affected the fairness of the experiment because they are a different type of metal compared to nichrome wire which has different properties and consequently different resistance. This means that the resistance of the nichrome wire showed up on both voltmeter and ammeter was slightly more than it actually was. I could have solved this problem by doing the following method:Firstly find the resistance of the connecti ng wire and the crocodile clips before each experimentThen, minus it from the overall resistance of the nichrome wire plus the connecting wires and the crocodile clips.Here is a formula I came up with to calculate the resistance of nichrome wire:N = R CWhere:N = the resistance of nichrome wire.R = the overall resistance of nichrome wire, the crocodile clips, and the connecting wires.C = the overall resistance of crocodile clips and connecting leads.Overall, I believe that the data provides sufficient evidence to support my theory and conclusions.I could have improved my investigation to support my analysis by doing other experiments such as the following I have also added a prediction for each factor from my own scientific knowledge:The diameter (cross-sectional area) of the wire:I believe that as the diameter of the wire increased, the resistance would decrease. This is because there are more space for the electrons to travel through, therefore less collisions.The temperature of the wire:I think that if the wire is heated up, the atoms in the wire will start to vibrate faster because of their increase in energy. This will cause greater collisions between the electrons and the atoms. So, there would be higher resistance.The material of the wire:I think that the type of material of the wire would affect the amount of free electrons. This is because the number of electrons depends on the amount of electrons in the outer shell of the atoms. If the material has a high number of atoms there will be high numbers of electrons causing a lower resistance because of the increase in the number of electrons. Also if the atoms in the material are closely packed then the electrons will have more recurrent collisions and the resistance will increase.

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Discussion 13 nur 702 Assignment Example | Topics and Well Written Essays - 250 words

Discussion 13 nur 702 - Assignment Example Thirdly, a gender dimension to my clinical problem exists and links available evidence with health policy. Burden of hypertension is greater among women than among men. American Heart Association (AHA) helps fight for strong public health policies that help in combating heart disease and can help with the first area. The AHA advances its mission through volunteer funds and research. American Kidney Fund can help in lobbying for health policy that would give patients financial support to help cater for their care and to conduct health education. HealthyWomen can help in foregrounding women issues that accrue from hypertension and heart disease mobilizing for health policy that would help address these issues. To get involved in health policy specific to my clinical problem, I will endeavor to contribute my evidence to the shaping the policy content. Additionally, I will be in the forefront showing the need to have laws that cover the issues that will be found to be pressing regarding the clinical problem. Finally, I will contribute in keeping surveillance ensuring that the policy is implemented and adopted (Brownson, Chriqui & Stamatakis,

FreeWill and Determinism Essay Example | Topics and Well Written Essays - 1000 words

FreeWill and Determinism - Essay Example nment and chains, social constraints such as threat of punishment and censure, as well as mental constraints for example genetic predispositions, compulsions, and neurogical disorders. These constraints make individuals not to have free will. One might tend to think that since he or she can examine his or choices, conscious of making decisions and can perform corresponding actions then there is free will (Chorney et al 28). This is not true. It is possible that one could have the opportunity of choosing freely even though in fact one can never do. Notable issue as far as free will is concerned is that we can’t prove that we have free will by just indicating out that it seems as if we do. It is clearly possible to have the experience of free will even if in reality we do not have free will itself. Compatibilists which means those who define free will without reference to determinism argues that determinism is compatible with free will. Additionally, they consider the argument between hard determinists and libertarians over free will versus determinism as untrue dilemma. Another notable aspect of the compatibilists is that not being caused is not enough condition for freedom but not even a needed condition. They argue that if an action is uncaused, it seems to be random. Their main view is that free actions are not uncaused actions, but it refers to the actions that are caused in a certain way. The compatibilist indicates that first an action is free if and only if its cause is internal instead of being external to the agent. However, it is worth to note that this is not a clear definition since an action can result to internal cause yet it is not free. For instance, even though sneezing has internal cause, it is not a free action. Secondly, they argue that an action is free o nly when it is due to agent’s beliefs and desires. Even though this seems to be acceptable, it is still faced with counterexamples since there are cases where an action is caused by

Explain the Muslim idea of Religious Authority Essay Example for Free

Explain the Muslim idea of Religious Authority Essay Revelations are the way in which we receive knowledge of God and this is done through the Holy Books. In the Christian tradition there is an understanding that the Bible is a medium of revelation (Prepositional view), this is where the truths recorded by God are recorded, there is also an understanding that revelation is the way in which God acts with human experience through history (non-prepositional view) In Islam religious authority comes from God via the Quran through the process of tanzil. The Quran tells them about God and gives them guidance this is the book in its guidance is sure without doubt. The Sunnah and the Hadith are also sources of authority. The Sunnah, which is the life example of the Prophet Mohammad, is a source of authority because he was a wise and trustworthy man who settled tribal disputes. The Hadith is also a source of authority because Muslims look to Mohammad because he showed true obedience to Allahs commands. The Imam also has authority, the Shiites believe the Imam possess spiritual ability and divine light but the Sunnis simply see the Imam as a leader of prayer who has no superior status. The Shariah is also part of religious authority because this is the Islamic law for Muslims and it gives all the basic rules and regulations as to how human beings should live and act in a political, economic, social and collective individual spheres. The Shariah looks at family life, inheritance, marriage, food regulations and divorce for example Muslims must eat halal foods, those that have been slaughtered by the neck vein being slit and blood drained whilst the name of Allah is invoked. Muslims follow the Shariah so that they are doing what is good and right according to God and removing evil from society, which works through the process of Greater and Lesser Jihad. Greater Jihad is about establishing maruf (right) and removing munkar (evil) from yourself A Muslim learns to control his own bad desires and actions. Lesser Jihad is the struggle of the Muslim community to remove haram from society. Evil will always exist in society and a Muslim must resist this by showing true dedication to Allahs commands. In Islam Allah is the main source of religious authority and to help Muslims to show they are showing their authority towards God, Muslims believe that Allah allows evil and suffering in the world to see if they do what is right. Muslims have free will and believe that everything is pre-determined and that Allah knows the present, the past and the future of every creature but this does not mean that man has and freedom of will, its just that they have the choice to obey or disobey Allah and that this will show on the day of judgement whether they will go to Heaven/ Hell because all their actions are judged. Religious authority from the Quran is seen to govern every aspect of life for example women in Islam are seen as the most important in the family. She is the one who should keep a halal home and to make sure food and dress laws are kept. The teachings of Islam is that women should have total equality in religion and education but they can never be fully equal, for example the husband has more power but with that comes a lot of responsibilities to perform The man has full responsibility for the maintenance of his family therefore a man has more inheritance than a womens because his need is seen to be greater. Through the 5 Pillars Muslims are seen to be showing obedience to Allahs commands this is because they are a very intense and personal struggle to abide by and through reading the Quran Muslims believe that it enhances there spiritual development because it is the word of God. They believe it is the pure word of God because it is seen to be a perfect copy of a timeless document. In Islam the Quran is more important than the Bile/Torah because they where seen to be distorted to suit their believing communities and the revelations in the Quran are believed to be recorded when Mohammad received them. The other basic beliefs of Islam such as Tawhid are also seen as authority. Tawhid implies that everything is created by Allah; it is the belief in Allah with all his powers. It is a source of authority because this is one way a Muslim fulfils Allahs commands as it reveals Gods loving and caring nature. From a non-religious perspective a philosopher would look to reasoning to emphasise human freedom to make moral choices. They would argue that all of humanity relies upon their conscience to decide what is right and wrong, and for many this authority does not come from God. However from a Christian perspective this higher level of consciousness comes from God. In Islamic terms we gain our conscious awareness from Quranic teachings about Akirah which gives us focus for this temporary life on earth, from taw hid which reveals the qualities of God that we should aim to develop in our own hearts (such as love and compassion), and Al Qadr which ultimately points to a pre-determined path which only God knows about he does not dictate.

Their Eyes Were Watching God :: essays research papers

From the time Janie was a child she had problems fitting in with her peers. This was partly because of her nice clothing, wonderful complexion, and long beautiful hair. Janie's grandmother encouraged her to be different from her peers. She wanted to make up for her past mistakes raising children by having Janie become the person that she never was able to be.   Ã‚  Ã‚  Ã‚  Ã‚  During Janie's early childhood she plays with the grandchildren of Ms. Washburn. It isn't until Janie is six years old that she realizes that she is black and different from Ms. Washburn's grandchildren. When Janie starts to attend school she is treated differently. Her classmates do not give Janie a chance to be friendly instead they decide Janie considers herself better than they are. This attitude causes Janie to make no friends at school.   Ã‚  Ã‚  Ã‚  Ã‚     Ã‚  Ã‚  Ã‚  Ã‚  When Janie is sixteen years old her grandmother marries her off to a potato farmer named Logan Killicks. Janie's grandmother feels that Janie needs to be married to a man that can take care of her so that she isn't wasted on someone who can not support her. The marriage to Logan does not work out for Janie. Logan sees her as a spoiled child who needs to learn to be a farm wife. Logan becomes one of the many people who do not give Janie a chance to be herself.   Ã‚  Ã‚  Ã‚  Ã‚  During her marriage to Logan Janie meets Joe Starks and runs off with him. Janie desperately wants Joe to be the one person to understand her and love her. However, what Joe sees in Janie is that she has class and he wants to make her one of his possessions. Janie's marriage to Joe looks ideal to many of the townspeople but on the inside she is very unhappy and still yearning to be loved.   Ã‚  Ã‚  Ã‚  Ã‚  When Joe dies many years later Janie meets a younger man named Tea Cake. She leaves the small town to Eatonville with him and they are married. It is with Tea Cake that Janie is finally happy. Living with him in the muck with the migrant workers Janie is able to discover her self, what she can do, and how fulfilling true love is.

Introduction to Duty of Care in Health and Social Care Settings

CU235P/CT235 Introduction to Duty of Care in Health and Social Care or Children's and Young People's Settings 1. Undestand the implications of Duty of Care. 1. 1 Define the term â€Å"duty of care'. Duty of care is an obligation that a person/healthcare worker acts towards others and public with watchfulness, attention and caution in a reasonable and civilized way. SU needs to know that his welfare, safety and interest are put in the centre of attention of any healthcare organisation. 1. 2 Describe how duty of care affects own work role.Every healthcare worker has a duty to act accordingly not just towards the clients but also their co-workers, other healthcare professionals and themselves. – following GCSS Code of Practise – keeping knowledge and skills up to date – not undertaking procedures outside own competences – acting in the best interest of clients – ensuring health, safety, welfare of clients – adhere to companies policies and proc edures 2. Understand support available for addressing dilemmas that may arise about duty of care. 2. 1 Describe dilemmas that may arise between the duty of care and an Individuals rights.Despite all the efforts of healthcare providers to ensure an Individual recieves the best possible care there might arise conflicts and dilemmas between healthcare worker and SU. Those conflicts may include: refusing a meal, type of activity, refusing medication or a treatment. Arising conflicts should be resolved as quickly as possible in a most satisfactory matter for both sides. The Human Rights Acts states that every person has the right to decide about own life, they can refuse the treatments and medication they recieve.It is essential to explain why they need that particular care and make them aware of pros and cons. 2. 2 Explain where to get additional support and advice about how to resolve such dilemmas. The Line Manager is the first person to turn to in any doubt. Family and friends of an Individual may be able to help. Other healthcare providers involved in care of an Individual. 3. Know how to respond to complaints. 3. 1 Describe how to respond to complaints. If an Individual is dissatisfied with provided care, he has the right to complain.Every company should have easy to access complaints procedure. When dealing with a complain on one to one basic healthcare worker should take the individual to a quiet and safe place, listen to an Individual carefully, be serious and polite, try to calm down the situation and apologise if necessary, inform an Individual about complains procedure. After the conversation with an Individual the healthcare worker should inform the manager. 3. 2 Identify the main points of agreed procedures for handling complaints.Every complain should be taken seriously and all the actions following a complain should be as quick as possible. If it's not possible to solve the problem straight after a complain, the manager should be informed. The conta ct with an Individual complaining should be polite and symphatetic. After talking the problem through the management should come up with a path of actions to solve the problem and arrange another meeting with the Individual to make sure the solution is satisfactory. All complains should be documented.