Lenzs Law And Faradays Law Of Induction :: essays research papers

Lenz's Law and Faraday's Law of Induction 1. With this definition of the flux being , we can now return to Faraday's investigations. He found that the magnitude of the emf produced depends on the rate at which the magnetic flux changes. Faraday found that if the flux through N loops of wire changes by an amount , during a time delta t, the average induced emf during this time is This fundamental result is known as Faraday's law of induction. The minus sign is placed there to remind us in which direction the induced emf acts. Experiment shows that an induced emf always gives rise to a current whose magnetic field opposes the original change in flux. This is known a Lenz's law. Let us apply it to the case of relative motion between a magnet and a coil. The changing flux induces an emf, which produces a current in the coil; and this induced current produces its own magnet field. If the distance between the coil and the magnet decreases; so the magnetic field, and therefore the flux, through the coil increases. The magnetic field of the magnet points upward. To oppose this upward increase, the field produced by the induced current must point downward. Thus Lenz's law tells us that the current must move by the use of the use of the right hand rule. If the flux decreases, so the induced current produces an upward magnetic field that is "trying" to maintain the status quo. Let us consider what would happen if Lenz's law were just the reverse. The induced current would produce a flux in the same direction as the original change; this greater change in flux would produce an even larger current, followed by a still larger change in flux, and so on. The current would continue to grow indefinitely, producing power (=) even after the original stimulus ended. This would violate the conservation of energy. Such "perpetual - motion" devices do not exist. It is important to note, which I believe was forgotten in the class lecture, is that Faraday's investigation, as summarized in Faraday's law, says that an emf is induced whenever there is a change in flux. Thus an emf can be induced in two ways: (1) by changing the magnetic field B; or (2) by changing the area A of the loop or its orientation theta with respect to the field. A motor turns and produces mechanical energy when a current is made to flow in it. You might expect that the armature would accelerate indefinitely as a result of applied torque. Lenzs Law And Faradays Law Of Induction :: essays research papers Lenz's Law and Faraday's Law of Induction 1. With this definition of the flux being , we can now return to Faraday's investigations. He found that the magnitude of the emf produced depends on the rate at which the magnetic flux changes. Faraday found that if the flux through N loops of wire changes by an amount , during a time delta t, the average induced emf during this time is This fundamental result is known as Faraday's law of induction. The minus sign is placed there to remind us in which direction the induced emf acts. Experiment shows that an induced emf always gives rise to a current whose magnetic field opposes the original change in flux. This is known a Lenz's law. Let us apply it to the case of relative motion between a magnet and a coil. The changing flux induces an emf, which produces a current in the coil; and this induced current produces its own magnet field. If the distance between the coil and the magnet decreases; so the magnetic field, and therefore the flux, through the coil increases. The magnetic field of the magnet points upward. To oppose this upward increase, the field produced by the induced current must point downward. Thus Lenz's law tells us that the current must move by the use of the use of the right hand rule. If the flux decreases, so the induced current produces an upward magnetic field that is "trying" to maintain the status quo. Let us consider what would happen if Lenz's law were just the reverse. The induced current would produce a flux in the same direction as the original change; this greater change in flux would produce an even larger current, followed by a still larger change in flux, and so on. The current would continue to grow indefinitely, producing power (=) even after the original stimulus ended. This would violate the conservation of energy. Such "perpetual - motion" devices do not exist. It is important to note, which I believe was forgotten in the class lecture, is that Faraday's investigation, as summarized in Faraday's law, says that an emf is induced whenever there is a change in flux. Thus an emf can be induced in two ways: (1) by changing the magnetic field B; or (2) by changing the area A of the loop or its orientation theta with respect to the field. A motor turns and produces mechanical energy when a current is made to flow in it. You might expect that the armature would accelerate indefinitely as a result of applied torque.

Internet and Our Social Life Essay

For a few decades now, the internet has been an important gear in the ticking clock we like to call everyday life. Its significance and usage is ever growing, as well as the number of areas in which it has crept in. The phenomenon that is the internet brought power at the click of a mouse, but as it goes with power, consequences are inevitable. The internet is, undoubtedly, the largest source of information today. It is also a practical tool for managing bank accounts, staying in touch with friends and communicating with people all over the world, with technology that enables you to simultaneously talk while looking at the person on screen and even hold video conferences. But practicality and availability of information are not the only things that attract internet users. In online social communities, forums and game rooms people are given the opportunity to be whoever they want to be. The internet gives us virtual clay which we can use to mold our identities in any way we want. Especially in game rooms, people tend to fantasize and invent characters in order to compensate for the lack of their own. That is how a regular John Doe can go to his boring work every morning, but come back home, turn his computer on and become Zyborg, the hero from outer space. The cyber space can be used as a resort when real life is difficult to deal with. For example, people with low self-esteem or people who lack social skills will probably find online chatting much easier than talking to the person face to face. Such use of internet can make one’s life more interesting or less stressful, but too much time and dedication to it can lead to serious social and psychological consequences. If a person spends too much time on the computer, with its virtual character and virtual friends, he develops a virtual life which he may prefer more than the real one. Consequently, even though he might feel satisfied and safe, he does more damage than good by neglecting some important parts of his regular life such as time with his family, health, responsibilities and productivity. Lately, a diagnosis called Internet addiction disorder has been introduced for people who are thought to spend too much time on the internet. This issue is facing its beginning and it i s still disputed whether it is a real disorder. But according to Dr. Maressa Orzack between 5% and 10% of internet users suffer some form of internet dependency and she lists withdrawal, loss of control, and compulsive behavior as some of the effects. Online dating sites, which people visit in order to find a partner for romantic or sexual relationship, have made courtship easier, but, paradoxically, there have been many cases in which the internet was the prime cause of ending a relationship, marriage or even filing lawsuits. With internet becoming more and more integrated into our lifestyles it is only normal that the effects, both positive and negative, be visible in all aspects of our lives, including socializing. It is nice to be able to see your sister who lives miles away smile for you on screen as if she were in the room with you, or exchange e-mails with a person who you normally wouldn’t have the courage to come up to, but it would be a scary thing if cafes would become empty and internet networks overloaded with Zyborgs.

Should Marriage Preparation Classes Be Required for Engaged Couples?

Many contemporary couples have problems in their houses because they were not prepared to get married. Furthermore, couples who were prepared have problems. In the last decade more and more couples are taking marriage classes before they get married. Many people reject the classes because for them it is a ridiculous thing. Also, they believe that a couple has to learn from its own problems, not with classes. Nevertheless, marriage preparation classes should be required for engaged couples because those classes teach the couples how to prepared for what is in store for them, deal with marriage troubles, and have confidence in their partner.These days, couples are marrying without the knowledge that you will get more responsibilities if you get married, and those couples must get more trouble at home. Therefore, marriage preparation classes prepare those couples who want to avoid those kinds of problems. All those classes prepare the couples and teach them about what is in store for th em. When someone gets married he or she has to acknowledge what kind of responsibilities he or she is getting.When people get married they lose many things that they used to do. They have to forgot too many hobbies, things they used to do and also friends. Moreover, they have to prepare themselves for children and all the responsibilities that a child give to someone. Furthermore, they have to support a family; they have to work, get a job, and so on. Those problems are taught by a marriage preparation class.There is another thing that a marriage preparation class teaches: how to deal with marriage problems. In the first or second year for a couple after they get married, maybe they will not have an encountered with any problems. However, when the responsibilities are increasing more and more the problems start to appear. Maybe those problems are: the husband is not at home too much time, the husband or wife’s salary is not enough to pay bills, they have a lack of time to be together and to share sentiments, and so on. When those problems appear, the couples start to be desperate and probably they will divorce. However, those couples who take the class know how to deal with those problems. They will know how to make a conversation with the partner without an argument.Marriage preparation classes make a kind of confidence in the couple. Those classes teach how to have confidence with the partner, and how to create confidence. The most common case of unconfidence is when he or she is thinking â€Å"My partner is having an affair†. The confidence in a relationship is the most important thing because it creates security and also love. Moreover, the confidence that a couple has in each other is important to make a stronger relationship. As a result, the husband or wife will not have any doubt about his or her husband or wife.In conclusion, the marriage preparation classes are very important to have a successful relationship in the future. Therefore, t hose classes should be required for engaged couples. When you will get married remember to be assisted by those classes, they will make you a better husband or wife. If you be assisted by those classes, your relationship will be better and comfortable.