The resistivity of Constantan Essay Example

The resistivity of Constantan Paper The resistance of a piece of wire is dependant on its length, cross-sectional area and the type of metal the wire is made of. The resistance of a given wire can be calculated using the following equation: R = ? L / A where: L = Length (m) A = cross-sectional area (mi ) ? = resistivity of the metal By rearranging the equation the resistivity of the metal can be calculated: ? = R A / L The resistivity differs depending on the metal however it is constant at room temperature for each metal. This means that two pieces of wire made of the same metal and at room temperature should give the same result when calculating resistivity regardless of its length and cross-sectional area. The following equation can be used to calculate the resistance of a wire: R = V / I where: V = volts I = amps R = resistance When rearranged it can be compared with the equation of a straight line graph: V = R I y = m x (where m = the gradient) This means a graph plotted with volts against amps, the gradient of the graph will equal the resistance of the wire and from this the resistivity can be calculated. We will write a custom essay sample on The resistivity of Constantan specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on The resistivity of Constantan specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on The resistivity of Constantan specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Constantan was chosen as unlike most metals, its resistivity does not change when the temperature is raised so the results will not be affected by the wire heating up. Method and apparatus Take two lengths of constantan wire, one 34 SWG (standard wire gage) and the second 30 SWG. Measure the diameter of each wire using a micrometer and then measure their lengths in metres. Set up the apparatus as shown in fig. 1 using the 30 SWG wire first and ensuring the power pack is on direct current. Using the rheostat alter the number of volts running through the circuit until approximately 3 amps is reached. Note the voltage and ensure the scale of volts used does not exceed this as the wire will get too hot. Use the rheostat to change the voltage to the first on your scale and note the amps. Repeat this until six readings have been taken. Set up the apparatus with the 34 SWG wire and repeat experiment. Plot a graph for each wire and calculate the resistivity of the constantan, both wires should give the same result. In the interest of safety all electrical appliances should be regularly checked. It is also important that the wire is not handled while in use in the experiment as it may heat up. To ensure little error the crocodile clips should be at the very end of the wire as the length is a factor in the calculation. If the wire curls onto itself and is touching at any point then this will affect the results as it will shorten the length of the wire the current must travel through. Apparatus: Ruler Voltmeter Micrometer Wires Rheostat Crocodile clips Power pack Amp meter Fig. 1 Results 30 SWG 34 SWG Volts i 0. 1 Amps i 0. 01 Volts i 0. 1 Amps i Discussion The resistivity of the two wires should have given the same result as they were both made from constantan, however the wires gave two different results. The 30 S. W. G. wire gave a result of 5. 49 x 10 ? m whereas the 34 S. W. G. wire gave a result of 4. 62 x 10 ? m. Although both wires gave a relatively close result to the expected value of 5. 49 x 10 ? m when tested, it does suggest some error was made. It was noted that all the experimenters present found they calculated a lower value for the 30 S. W. G. wire than that of the 34 S. W. G. wire. This may mean that the properties of the two wires differ slightly, perhaps because of a difference in the company that produced it or a different batch. The equipment used was limited as to how accurate the readings could be with the accuracy being i 0. 01 for the ammeter and only i 0. 1 for the voltmeter. This may have affected the results and could account for why the graph for the 34 S. W. G. wire did not form a straight line and so a line of best fit had to be drawn. The graph for the 30 S. W. G. did form a straight line as expected so perhaps there was less error in the testing on this wire. If the experiment was to be repeated, a more accurate voltmeter and ammeter should ideally be used. It may also be beneficial to use wires that come from the same batch and company to ensure this is not a factor affecting the results. Bibliography Kaye and Laby (1995) Physical and Chemical Constants 16th Ed : Longman Carol Slack Show preview only The above preview is unformatted text This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section.

Free Essays on The Lark Above The Trenches

as â€Å"guns† and â€Å"hell†. The bleakness definitely comes through the poem, with haunting images such as â€Å"men gasping their lives away†. This desperate and chilling image is continued with the winter feeling â€Å"ice-cold†. Winter has negative connotations, especially when there is no escape for these men and they are stuck outside. This harsh reality is interrupted by the lark who boosts the morale of the men by its song raising their â€Å"wounded hope†, suggesting that life is reaffirmed and hope is renewed by the wonderful song. In this poem the elements of desolation and hope are finely bal... Free Essays on The Lark Above The Trenches Free Essays on The Lark Above The Trenches An appreciation of â€Å"The lark above the trenches† by Muriel Elsie Graham Many poems written in response to the events of the 1914-19 war are the products of direct experience of the processes of war – making weapons, nursing the wounded, the loss of brothers, sons or lovers in the trenches – by women in active service in the battle areas as well as by women involved in the war effort at home. The range of this poetry is wide. It is often experimental and in advance of the male poetic response. Muriel Graham has been inspired to write this poem by the newspaper cutting presented at the beginning of the poem. Immediately by reading this epigraph we already recognise the contrast of the beautiful song of the lark with the terrible situation that these soldiers are in. In each stanza, this poem expresses a profound and sombre uncertainty for the soldiers. However, the contrast is reiterated at the end of each stanza, with the reminder of the lark’s song, and we have a glimmer of hope. The opening of the poem is very grim and negative. The repetition of â€Å"all† emphasises the drudgery of these soldiers’ lives. Also adding to that emphasis is the continual regular rhyming pattern (ABCCAB) this definable sense of rhythm is furthered by the use of iambic pentameter, which often emphasises such negative words as â€Å"guns† and â€Å"hell†. The bleakness definitely comes through the poem, with haunting images such as â€Å"men gasping their lives away†. This desperate and chilling image is continued with the winter feeling â€Å"ice-cold†. Winter has negative connotations, especially when there is no escape for these men and they are stuck outside. This harsh reality is interrupted by the lark who boosts the morale of the men by its song raising their â€Å"wounded hope†, suggesting that life is reaffirmed and hope is renewed by the wonderful song. In this poem the elements of desolation and hope are finely bal...

Final Strategic Plan Research Paper Example | Topics and Well Written Essays - 750 words

Final Strategic Plan - Research Paper Example The company should ensure that production of customized soft drinks is according to customers’ remarks and interests (Morris, Honeycutt & Pitt, 2001). For example, an effective tactic is to launch a commentary channel program that allows customers to give comments. Another strategic plan is to establish the business to countries globally, and consider the diverse cultural practices of each race. For a successful business operation, Doll Beverage Company will have to launch an effectual program dealing with social concerns. Lastly, coming up with a policy that controls the behavior and relations of the organizations’ personas to clients ensures that professionalism is maintained during business operations (Morris, Honeycutt & Pitt, 2001). Doll’s beverage Company should use its strength of being new in the market to begin a program that deals with marketing and attracting innovators. The strategy will assist the company to develop and acquire new customers. Example s of other marketing stratagem and tactics that Dolls Beverage Company can implement are establishing; higher returns on invested capital and an attractive economic value added (EVA) performance. Moreover, it ought to establish; lower costs compared to key rivals and competitors in the market, and higher levels of customer satisfaction than competitors (Morris, Honeycutt & Pitt, 2001). ... A further marketing and information technology strategy and the scheme is the use video conferencing. The tactic is used in organizations commonly because of its efficiency and speed to a large group of people. Clients and personalities of an organization can transmit information quickly and easily, hence making business operation valuable (Morris, Honeycutt & Pitt, 2001). Section 2 Firstly, the methods that Doll Company can use to monitor and control proposed strategic plan include escalating its revenue sales in order to improve the overall income. For example, the management of the organization can set a target of increasing their revenues by 15% each year. This step will make Doll Beverage Company improve its increased income by an outstanding 7%; hence maximizing and improving the worth of the shareholder. Consequently, the organization increases its overall financial constancy since it will have many interested shareholders who would assist in completing the organizationâ€℠¢s programs and projects. Secondly, the next step is to improve their market share is a significant factor that monitors and controls proposed strategic plan and advance organizational objectives financially. The fact that the company is new in the business world gives it opportunities of succeeding both in home and foreign countries exceptionally. For example, Dolls Company can set an objective of increasing and improving the market share by a range of 15% annually by initiating new outlets in the five jurisdictions every year, since their accessibility to the more clients will be achieved by implementing the method. Lastly, the method Dolls Beverage Company that can be used to