Nichrome wire by determining its resistivity Essays

Nichrome wire by determining its resistivity Essays Nichrome wire by determining its resistivity Paper Nichrome wire by determining its resistivity Paper Metals have low resistance due to their delocalized field of electrons. However, different metals have different values of resistance. In this experiment, the students were given a spool of Nichrome wire to determine its diameter. Nichrome, as the name suggests, is an alloy of Nickel, Chromium and Iron.  The resistance of a conductor depends on its inherent resistivity (Ï ), length (l) and its cross-sectional area (A). The resistance is given by the following formula (#1): . Where, R = Resistance (à ¢Ã‚ ¦)  Ã  = Resistivity (à ¢Ã‚ ¦.m)  l = length (m) and,  A = cross-sectional area of the conductor.  To determine the cross-sectional area of the wire, the diameter was first determined using a micrometer screw gauge. The formula (#2) that relates the diameter to the cross sectional area of the wire is:  The electrical resistance can be determined by an ohmmeterlength, using a ruler, and the resistivity was determined by the literature value of 1.25Ãâ€"10-6 à ¢Ã‚ ¦.m.[1] Substituting the literature value for Nichrome’s resistivity () and formula #2 into formula #1, the following equation can be obtained: This equation can graphically represented by l on the y-axis and R on the x-axis. The gradient would then give the value for which could then be manipulated to extract the value of d. A simple circuit was set up with the Nichrome wire as the resistor. For different sets of data, the length of the Nichrome wire was altered by making only a fraction of the full wire part of the circuit. A ruler was used to measure the length of the wire part that was part of the circuit and an ohmmeter was used to identify the resistance of the circuit. Five trials were taken for five different lengths to obtain a reliable, wide range of data. Safety Precautions:  1. Precaution was taken so that the Nichrome wire would not hurt the finger.  2. Precaution was taken to make sure there were no fire hazards due to short-circuit.  3. Precaution was taken to make sure that no injury was caused because of electrocution due to careless behavior.  RAW DATA COLLECTION:  The resistance of the circuit for different lengths were collected as raw data and are tabulated below:  Therefore, using the ‘resistivity’ method, the diameter of the Nichrome wire is identified to be 0.053  ± 0.001cm. CONCLUSION AND EVALUATION: As it can be seen from the total uncertainty calculation, the experimentally deduced value of the diameter of the Nichrome wire was accurate to a large extent. In fact, the literature value provided by the manufacturer†¦ The difference†¦Ã‚  The r2 value for the line of best is 0.9956 which shows excellent linear correlation between the resistance and the length of a conductor, confirming the equation However, the minor noticeable distance between the average slope and the minimum and maximum slopes is due to the increasing uncertainty in the measurement of the length. The uncertainty, however small, cannot be ignored and they must be explored so that if possible, they can be avoided in the future. Firstly, the recording of the length of the Nichrome wire was no so accurate because of the uncertainty in the ruler and its inability to measure all the lengths at one go. A longer ruler or a measuring tape could be used to avoid these kind of easily avoidable errors. Another problem was that the wire was often crooked at some places and straightening it could have caused it to crack so they were not completely straightened. In fact, the wires were looped around several bobs and the distance between the bobs were measured to give an accurate estimate of the length of the wire. Another issue that arose due to the usage of the bobs was that it was difficult to measure the length of the wire that was used to complete the loop around the bob. A possible workaround both these problems can be to use a thread to run along the Nichrome wire and then measure the thread to determine the length of the Nichrome wire used. Another limitation to the procedure of the experiment is the assumption of the electrical resistivity of the Nichrome wire. The actual range is 1.00 to 1.50 (Ãâ€"10-6 à ¢Ã‚ ¦.m) but the median, 1.25 was assumed. There is no possible way to tell the exact electrical resistivity without knowing the exact composition of the wire and this is because resistivity is a property that is specific to the composition of the conductor and slight changes in the composition can produce significant changes in the value for the resistivity of the conductor. Depending on the manufacturer’s label for the diameter is accurate but often these values are rounded off to suit the gauge number of the wire. For example, if a 2AWG wire requires a 10mm diameter, most manufacturers will label even a 9.8mm to be 10mm because of their own economic benefits. Therefore, the most accurate way would be use a micrometer screw gauge to measure the diameter of the wire at different locations and then match the experimental value obtained from this experiment against the average of the micrometer readings. This way, dependence on secondary data is minimized and a higher level of confidence can be displayed in the readings.

32 Interesting Facts About Princess Diana

32 Interesting Facts About Princess Diana Diana was popularly called Princess Diana, but this is not her proper title. Before marriage, and after her father became Earl, she was Lady Diana. After marriage, she was Diana, Princess of Wales. She was permitted to keep that title, though not Her Royal Highness, after her divorce from Prince Charles. Lady Diana had an aristocratic upbringing in England and quickly became an adored member of the British royal family. Her passions included interest in music, dance, and children. Diana passed away in a tragic car crash in 1997 while visiting Paris, during an escape from the paparazzi, where it was soon discovered that the driver of her taxi was under the influence of alcohol. 32 Interesting Facts About Princess Diana Diana, Princess of Wales, was 510 tall.Diana was a commoner and not royal at her marriage. She was, however, part of the British aristocracy, descended from King Charles II.Dianas traces her lineage to King Charles II through her father. Diana was related to Winston Churchill and 10 U.S. presidents: George Washington, John Adams, John Quincy Adams, Calvin Coolidge, Millard Fillmore, Rutherford B. Hayes, Grover Cleveland, Franklin D. Roosevelt, and both Bush presidents.  She was also related to the actor Humphrey Bogart.Her stepmother was the daughter of famous romance novelist Barbara Cartland.She grew up with two sisters and two brothers.  The siblings were close in childhood.Charles dated one of Dianas older sisters before he dated Diana.Diana won an award at school for taking good care of her guinea pig.At school, she was talented in music and especially on the piano.After graduation, she took a course in cooking on the advice of her mother.Queen Elizabeth II is the godmotherà ‚  of Dianas brother. Four of Dianas ancestors were mistresses to British kings.Diana was the first British citizen to marry an heir to the British throne since 1659 when the future James II married Anne Hyde. Queen Elizabeth IIs mother was a British citizen, but when she married the future King George VI, he was not the heir apparent to the throne; his brother was.Prince Charles proposed at Buckingham Palace on February 3, 1981.At the time of her engagement, Diana was working in a preschool playgroup as an assistant.Dianas ring, with 14 solitaire diamonds and a 12-carat sapphire, is worn today by her sons wife, Kate Middleton.Diana was 12 years younger than Charles.Her wedding had a television audience of 750 million.Diana met several times with Mother Teresa, including in the Bronx, New York, in June of 1997. Ironically, Mother Teresas death on September 6, 1997, was practically eclipsed by the news surrounding Dianas funeral. Diana was buried with a set of rosary beads given to her by Mother Teresa. Prince Charles 1994 television interview with Jonathan Dimbleby drew a British audience of 14 million viewers. Dianas 1994 television interview on BBC drew 21 million viewers.Dianas tragic death has been compared to that of Marilyn Monroe and Princess Grace of Monaco. Diana attended Princess Graces funeral as her first official state visit abroad. Elton John adapted his tribute to Marilyn Monroe, Candle in the Wind, for Dianas funeral, and recorded the new version to raise money for causes Diana had supported.Some 2.5 billion people around the world saw at least some part of her funeral via television or in person.Her grave is on an island in an ornamental lake on her familys estate, Althorp Park. The site is surrounded with four black swans guarding the tomb and oak trees numbering 36, for the years of her life, are on the path to the grave.$150 million in donations were received in the week following the creation of the Diana, Princess of Wales Memorial Fund right after her death. This fund continues to support many causes that were important to her during her lifetime. Among many charities supported by Princess Diana was the International Campaign to Ban Landmines. This effort won a Nobel Peace Prize a few months after her death.Another issue important to Diana was HIV/AIDS. She worked to end the stigma against people with the illness and for equality and compassion for those affected.In 1977, Diana taught Charles to tap-dance. They did not start dating until 1980.While Charles loved polo and horses, Diana had little interest in horses after a fall from a horse. However, she developed an interest in her riding instructor, Major James Hewitt.In a 1995 BBC interview, during her separation from Charles and before their divorce, she admitted that she had committed adultery during her marriage.  This was after it was revealed that Charles had had an affair.Her autobiography details mental health issues including eating disorders and suicide attempts.Her divorce settlement included a lump sum of $22.5 million and an annual income of $600,000 per year t o continue funding her office. Diana was on the cover of Time magazine eight times, Newsweek seven times, and People magazine more than 50 times. When she was on the cover of a magazine, sales soared.Camilla Parker-Bowles, after her marriage to Prince Charles, could have used the title Princess of Wales but chose to use Duchess of Cornwall instead, deferring to the public association of the former title with Diana.