Wire affects its resistance Essay Example for Free

Wire affects its resistance Essay Current: Current is the movement of electrical charge the flow of electrons through the electronic circuit. Current is measured in AMPERES (A). A current is a flow of electrons, the higher the current the more electrons flow round the circuit every second. Batteries can make electrons move. They can push electrons through wires made of copper and other metals. Materials like copper let electrons flow through are called conductors. The tiny electrons squeeze between the atoms in the wire. Some materials stop electrons passing through, these are called insulators. Plastics and rubber are insulators. The voltage will be measured so I will be able to calculate the resistance using Ohms Law. The current will be kept the same throughout the experiment and then will be used also to help me find the resistance using Ohms Law. (`Wires Wires warm up when a current flows through. Thin wires warm up much more than thick ones, and some types of wires warm up more than others. They warm up because of collisions inside the wire generating heat. If too much current were passed through a wire it would melt. (`ElectricityElectricity is lots of tiny particles called electrons moving along a wire. Electrons are much smaller then atoms. In fact, they are parts of atoms, so there are electrons in everything. (`Circuit A circuit is a path for electrons to flow through. The path is from a negative terminal power source, through the various components and onto the positive terminal. Think of it as a circle, the paths may split of here and there, but they always form a line from the negative to the positive. NOTE: Negatively charged electrons in a conductor are attracted to the positive side of the power source. This helped me to set up my circuit. ( `Conductor A conductor is a material (usually a metal) that allows electrical current to pass easily through. The current is made up of electrons. This is apposed to an insulator, which prevents the flow of electricity through it. Even good conductors have some resistance to flow through it. The conductor that I am going to use is copper wire, which has resistance. Electrons need energy from the power source (in this case a power pack) to travel. The further they have to travel, the more energy it takes so the resistance increases. In Metals The Current Is Carried By Electrons 1. Electric current will only flow if there are charges, which can freely move. 2. Metals contain a sea of Free Electrons (which are negatively charged). And flow throughout the metal if they are given energy. 3. This is what allows electric current to flow so well in materials. ( `Resistance Resistance is anything that causes an opposition to the flow of electricity in a circuit. It is used to control the amount of voltage and /or amperage in a circuit. Everything in a circuit causes a resistance (even wire). It is measured in OHMS (? ). Resistance occurs when the electrons travelling along the wire collide with the atoms of the wire. These collisions slow down the flow of electrons causing resistance. Resistance is a measure of how hard it is to move the electrons through the wire. The resistance of a wire depends on the number of collisions the electrons have with the atoms there will a larger number of collisions which will increase the resistance of the wire. If a length of a wire contains a certain number of atoms, when that length is increased the number of atoms will also increase. E. g. If there is a wire that is half the length of another wire it would also have half the number of atoms, this means that the electrons will collide with the atoms half the amount of times. Also if the length of the wire is trebled or quadrupled then the resistance would also treble or quadrupled. My prediction was derived from this information. All of this information I collected originated from the Website, www. studentcentral. co. uk from encyclopaedias such as The Oxford Childrens Encyclopaedia and computer encyclopaedias such as Encarta. (This scientific information relates to my experiment by stating that the longer the lengths of wire the higher the resistance. (Preliminary Results Length Of Wire (mm): Voltage (V): Current (A): Resistance (? ). (Therefore this information supports my prediction that the longer the length of wire the higher the resistance. Obtaining Evidence: (The variables I kept the same are: (The same material used for the wire, (The same cross-sectional area of wire, (And the same temperature of the wire. (The potential difference from the power pack: 2V. (The current, which measured the rheostat, was kept at: 0. 5A. (The lengths of the copper wire: (0 mm, (100 mm, (200 mm, (300 mm, (400 mm, (500 mm, (600 mm, (700 mm, (800 mm, (900 mm, (1000 mm. (The readings from the voltmeter and the ammeter were measured to two decimal places. Test One: Length Of Wire (mm): Voltage (V): Current (A): (These tests are reliable because you can see patterns, which is as the length increased the resistance increased. (It is a suitable range of lengths because I have done over six sets of results (0 1000 millimetres), so I will be able to identify a line of best fit to show my results. (My results are accurate, as they show as the length of the wire increased the resistance increased proportional to it. Averages: Length Of Wire (mm):Voltage (V): Current (A): Resistance (? ). (To find the resistance I divided the voltage by the current, e. g. Length of wire 100mm: Resistance = 0. 02 0. 5 Resistance = 0. 04 ? (My results show as the length of the wire increased the resistance increased proportional to it. I know this because my graph shows a fairly strong positive correlation, which tells me that as the length of the wire increases the resistance of the wire increases, proportional to it. (Also my results show when I started at zero (0 millimetres) it was a good control to show no change. (The results were not exactly proportional as I expected, but the graph still justices my prediction that as the length increases the resistance increases also. This was because the longer the wire the more electrons there were, subsequently it was more likely that the electrons were going to collide with other electrons, thus there was a higher resistance. (The resistance depends on the number of collisions there were between the atoms of the material, which was copper. The length of the wire affects the resistance because the number of atoms in the wire increases as the length of the wire increases in proportion. Hence there is a higher resistance. Evaluating Evidence: (I think that the procedure of the experiment was fairly accurate as I recorded my results to two decimal places and also because on my average table of results the increase in resistance could be easily identified. Overall I think that my procedure during the investigation was well planned out. (The main problem I had was when I was reading the ammeter and the voltmeter as the readings kept fluctuating and took time for the readings to settle down, which as a result affected my results. (The ranges between my results were small and fairly close on the tables, which indicated accuracy. Although when I converted my results into a line graph I found that six out of the eleven results were anomalous results, which was probably due to human error and probably due to defaults in the meters, as they were battery powered. Also the sensitivity of the meters as they were not very sensitive and therefore my results were affected by this. (Even though there were anomalous results they were fairly close to the line of best fit as they were either just above or just below the line of best fit. Therefore the results were quite accurate and so I felt that I did not need to repeat any of the results and that I did not need to record any more results, as the results still justified my prediction. (Furthermore I could have changed the line of best fit so that more of the results fitted in with the line. (The improvements I could have made to make the results more accurate would be to use a much more sensitive ammeter and voltmeter, so I could have recorded my results to three or four decimal places, which would have made my results more accurate. Moreover I could have had shorter length ranges to show better accurate results, to see how a small increase in length affected the resistance compared to a large increase in length. So I could have use the range of lengths from zero millimetres to twenty millimetres to 40 millimetres and so on rather than the range I chose, which was zero millimetres to 100 millimetres to 2000 millimetres and so on, which therefore would have affected the results (resistance). As a result this would have shown the pattern better, clearer and easier to point out and it would have improved the line of best fit. Wednesday 27th 2001 F. Nazmin Hussain 10. E.

Times May Not Be A’Changin’ :: essays research papers

Times May Not Be â€Å"A’Changin’†   Ã‚  Ã‚  Ã‚  Ã‚  Although portrayed in a particularly gruesome scenario, author Shirley Jackson conveys the importance of upholding tradition in her short story, â€Å"The Lottery.† While the climactic execution-by-stoning isn’t quite a modern example, it still serves to show us that some traditions are worth upholding. In our society today, it seems as if there is a growing movement to look forward and embrace the new instead of remembering our past. But to effectively make changes and plan for the future, it is essential that we turn to our history. One of the greatest issues in the world today is that of patriotism. In the immediate wake of September 11th, nearly all residents of this country proudly proclaimed themselves â€Å"Americans,† putting aside personal bias, differences in religion, and family roots to support the rebuilding of a nation. Lately, however (since our involvement in the Iraq War), this notion of unity and brotherhood has once again ta ken a backseat to personal agendas.   Ã‚  Ã‚  Ã‚  Ã‚  In the same way that the town is proud to continue its June 27th tradition, most people also take pride in feeling allegiance towards their country (specifically the United States). Perhaps it is deep family roots or a strong connection with constitutional ideals; whatever the reason, patriotism seems to stick with Americans. Even though our interest in our country has been at an ebb and flow since the beginnings of the Revolution, we tend to strongly identify with this nation. The small town has a grizzly ritual that leaves at least one person each year particularly unhappy, yet we do not hear talk of moving away. We only read of other towns that have done away with the lottery: â€Å"They do say†¦ that over in the north village they’re talking of giving up the lottery (McMahan 87),† and there is â€Å"nothing but trouble in that (McMahan 87).† Even Tessie Hutchinson, the unlucky ‘winner,’ claims that the practice is unfair, but nonetheless goes along with it. Analogously, a soldier who dies for his country does so for the greater good. The soldier is so passionate about the ideals of his nation that he is willing to die defending them. He does not want to die, but knows he is doing so for a good cause – that of liberty.   Ã‚  Ã‚  Ã‚  Ã‚  The townspeople are not fighting for their freedom from oppressors or antiquated ideals; on the contrary, they are struggling to maintain their heritage.

Advantages of mass media Essay

Mass media refers collectively to all the media technologies that are intended to reach a large audience via mass communication. There are various forms of mass media such as radio, television, movies, magazines, newspapers and the World Wide Web. Mass Media enjoys a very prominent role in our lives and thus, it is believed to influence our society. There are positive and negative effects of mass media on our society. This essay will discuss the advantages and disadvantages of mass media and state if the advantage or disadvantage outweighs the other. The first advantage of mass media is that it promotes democracy. Talk shows and debates that are conducted on the radio gives people chance to voice out their opinions and express their views of ideas about a particular issue. This use of radios makes it a â€Å"free market place of ideas† where people get informed of the multiple ideas that can be learned about a topic. Also this advantage of mass media allows arguments to be otherwise of the discussed perspective of an issue to voice out the contrasting feelings of people without the fear of being pointed to by the authorities if opinions are subjective. Moreover, free press keeps the government under constant monitoring and checks. It helps the general public to question issues that highlight policy failures, maladministration, scandals and corruptions and this makes mass media the voice of the disadvantaged. A long tradition of liberal theorists claimed that a free and independent press within a nation can play a vital rol e in the process of democratization by contributing towards the right of expression, thought and conscience, strengthening the responsiveness of government to all citizens and providing a pluralist platform of political expression for a multiplicity of groups. Thus, radio being an example shows the positive relationship between mass media and democracy. Read more: Advantages and Disadvantages of Mass Media Furthermore, mass media promotes health education. A way in which societies can grow is through good health and studies assert that media has a responsibility to help people live a healthy life. In Uganda, for instance, FM radios conducted programs where medical doctors were invited to a program  to talk about general or specific diseases, their causes, symptoms and how to avoid these diseases or where to seek treatment. Namely, Radio-Wa conducted a program, Meet The Doctor, on which a doctor from Lira Hospital appeared every Sunday from 5.00 pm and discussed popular medical issues, such as, current health problems of reproductive health diseases and sexually transmitted diseases, for about an hour. Through another research, it was found that radio listeners took active part in these kinds of programs and they were able to learn about many diseases that they were suffering from unknowingly. Majority of the listeners were able to cure their diseases. Thus, mass media assists people to keep informed about medical and health issues. In addition, mass media plays a very vital role in accounting for agricultural trade. Radio, one of the fastest forms of mass communication, has been used in communicating farm information to farmers for a long time and since then radio has been used as a mass communication for agricultural development. Rural communities need information on supply of input, early warning systems for drought and diseases, new technologies and market price and information about their competitors. Such information through mass media contributes to the expansion of agriculture. After looking at factor such as the continuing expansion of market oriented agriculture and the increasing complexity of input requirements, studies suggested that there is a need for a continues education of farmers and extensions and thus concluded that radios and television would be a good way to disseminate information to them. Another research showed that 58 % of the respondents regarded radio as the most effective channel fo r dissemination of agricultural information. Thus information about trade from mass media would likely result in benefiting the whole economy along side with the entrepreneurs of such trading businesses. On the other hand, mass media broadcasts negative information to teen agers, especially females, about sex related topics. Movies and televisions are two examples of sources from where teens absorb information about sex and sexuality. These sources give unrealistic images of the portrayed topics. A study shows that an average teen ager is exposed to approximately 14000  references of sex of which less than a percent of the references imply information about abstinence, birth control, pregnancy risks, and sexually transmitted diseases. In addition, mass media uses females as sex objects. In most music videos, females are approximately half the time dressed in clothes that expose their breast and rear ends. The sexual attractiveness of music videos and similar imaged mass media encourages teens as well as adults to expose themselves in public, inviting them to become victims of unethical crimes, such as, rape. Moreover, mass media depicts non realistic body images. This disadvantage of mass media depiction leads majority of the viewers toward unhealthy eating habits. Young people are getting encouraged by skinny models on the TV to lose weight and get their body into a sexy image. Researchers are claiming that males are becoming more insecure about their physical appearance as advertisements are painting images of idealistic well built muscular body. A study found that girls as young as eight years old are weight conscious and are on strict diets. Many other females smoke to keep their weight off and through research, it is found out that there is approximately 400% increase in eating disorder since 1970.Like females, boys also tend to smoking to lose weight. A survey by Teens Magazine reported that 27% of the females felt that media pressured them to have a perfect body and 69% of girls state that magazine models influence their thought of being slim and slender. Media’s role in po rtraying unrealistic images of body figures can lead to serious health problems and deadly diseases as attendants to media are evidently being influenced by the false images. In addition, mass media promotes gender and racial unfairness in a society. Women, through media, are treated in disrespectful manners and are referred by the use of unethical words, such as, â€Å"a whore† or â€Å"a slut†. These kinds of words can be heard over the radio and seen in movies and televisions, for instance, the use of the word â€Å"bitch† in reference to women can be seen in wrestling programs exposed young children to witness it without supervision. Advertisements also promote gender biasness as they mostly include women in a sexual way to sell product. A study on advertisements showed that males are only seen in 25% of the advertisements on scantily wears, for example,  underwear advertisements. The same study quoted that roughly 62% of white women were noticed in the same kind of advisements and the figure for black women was 53% only. Also, black women were mostly shown in animal prints and in predatory poses to highlight their powerlessness . Thus, mass media is openly bias towards the sexes and races of different kinds of people. Besides its other disadvantages, mass media is known to lead young children to aggressive violence. Media violence is harmful to kids because of their inability to differentiate between reality and fantasy. A study showed that by the age of 18, an average teen ager has viewed approximately 200000 acts of violence on television, ignoring other sources of mass media. These violent clips increase aggressiveness and anti social behavior in children and it also increases their thirst for violence in the real life. Hence children are traumatized by the violent images and as a result they end up committing violent acts themselves. In conclusion, it is clearly argued that mass media has both advantages and disadvantages. The issues that are discussed in this essay evidently suggest that the disadvantage of mass media outweighs the advantages yet some of the disadvantages of mass media can be avoided.

The Meaning of Nani in Japanese

The word nani  Ã¤ ½â€¢ (㠁 ªÃ£  «) in Japanese means what. And depending on the situation, you might, instead, use  nan (㠁 ªÃ£â€šâ€œ). Which term you use depends on the context, in particular, whether you are speaking or writing formally or informally. The sentences below are listed first in a transliteration of the Japanese phrase or sentence, followed by the spelling in Japanese characters—using  kanji,  hiragana, or  katakana  as appropriate—followed by the translation in English. Where indicated, click on the link to bring up a sound file and hear how to correctly pronounce the word or sentence in Japanese. Using Nani or Nan in a Sentence Nani is the more formal and polite term to use when asking a question, as in: Nani  wo  suru  tsumori  desu ka? (㠁 ªÃ£  « ã‚’ 㠁™ã‚‹ 㠁 ¤Ã£â€šâ€šÃ£â€šÅ  㠁 §Ã£ â„¢ 㠁‹)   What do you intend to do? or What are you planning to do? In more casual situations it would  be  fine to use nan. As a general rule,  if the word following what begins with a syllable from the t, n, and d groups, use nan, as in: Nandeshou? (㠁 ªÃ£â€šâ€œÃ£  §Ã£ â€"ょ㠁†) What do you want? More on Using Nan vs. Nani Nan is used before  particles.  A particle is a word that shows the relationship of a word, phrase, or clause  to the rest of the sentence.  Particles are added to the end of sentences to  express the speaker  or writers  emotions, such as doubt, emphasis, caution, hesitation, wonder, or admiration. You might use  nan   with a phrase such as /㠁 ®, /㠁 § (which means of the and is pronounced no de)  and verb da/desu (打㠁 §Ã£ â„¢ ), meaning it is hitting or it is striking. Nani is used before: /㠁‹ (meaning or and pronounced as ka)  and /㠁 « (meaning into a and pronounced as ni). Be careful when you use nan because, for example, if you use  nan  before ka  (/㠁‹), which means or, it would sound like the word nanka  (㠁 ªÃ£â€šâ€œÃ£ â€¹), which means things like. Another example would be if you were to use  nan with  ni (/㠁 «), it would be nanni  (㠁 ªÃ£â€šâ€œÃ£  «), meaning why, but this sounds very much like nannimo  (㠁 ªÃ£â€šâ€œÃ£  «Ã£â€šâ€š), which translates as nothing at all. Using Nani or Nan in Context You might use  nani  or  nan  in a restaurant. Depending on whether you are at a formal business luncheon or a casual eatery, you might use either of these terms. For example, at fast food eatery you might say: Osusume wa nan desu ka.  (㠁Šå‹ §Ã£â€š Ã£  ¯Ã¤ ½â€¢Ã£  §Ã£ â„¢Ã£ â€¹) What do you recommend?Are wa nan desu ka. (㠁‚ã‚Å'㠁 ¯Ã¤ ½â€¢Ã£  §Ã£ â„¢Ã£ â€¹Ã£â‚¬â€š) What is that?   If you are at a more formal eatery, but you dont know what to order, you might ask a fellow diner: Nani ga oishii desu ka. (ä ½â€¢Ã£ Å'㠁Šã â€žÃ£ â€"㠁„㠁 §Ã£ â„¢Ã£ â€¹Ã£â‚¬â€š) What is good? If you are traveling on a train and need to ask for help from a stranger or train conductor, that would be considered a more formal situation in Japan. Thus, you would use  nani  and might say: Tsugi  wa  nani  eki  desu ka.  (æ ¬ ¡Ã£  ¯Ã¤ ½â€¢Ã© §â€¦Ã£  §Ã£ â„¢Ã£ â€¹Ã£â‚¬â€š) What is the next station? However, if you are traveling with a friend, you might use   the informal  nan, as in: Nan-ji  ni  demasu  ka.  (ä ½â€¢Ã¦â„¢â€šÃ£  «Ã¥â€¡ ºÃ£  ¾Ã£ â„¢Ã£ â€¹Ã£â‚¬â€š)   What time does it leave?