Resistance And Length Of Wire Essay Research

Paper

IntroductionElectric charge on an

object is often called static electricity. Objects charge up because they gain

or lose electrons. The electron is the smallest part of the atom. The electron

carries a fixed negative charge. Every atom has a positively charged nucleus

surrounded by electrons. An atom is uncharged because it contains equal amounts

of positive and negative charge. Current is a flow of electrons. It is measured

in amps. A circuit can be in series or parallel. In a series circuit the parts

are placed one after another. If you remove a part the circuit is broken. A

parallel is different because the bulbs are placed opposite to each other. Voltage pushes

electrons around the circuit. It is measured in volts. Ammeters are used in

series circuits and voltmeters in parallel circuits. To measure the resistance

in a circuit you use this formula:VOLTAGE CURRENTThese are some factors

that may effect my results:1. The starting and

stopping of the stopwatch may not be 100% accurate. 2. The wire may not

give an accurate reading due to frequent use. 3. If you do one

experiment and then another straight after the warmth of the wire may effect

the results.Method1.? Connect the crocodile clip (that is joined

to the volt meter) to the wire at 10 cm and get a reading of amps and volts. 2.? Repeat this for 20,30,40,50,60,70,80,90 and

100cm. 3. Rcord the results

in a table and plot them onto a graph.PredictionI predict that the

longer the wire the higher the resistance. This is due to the fact that the

electrons in the wire have to travel further. If the wire is longer the

electrons will take longer to push through all of the atoms.Fair TestTo make my experiment

a fair test I will set the experiment up accurately and keep the Power pack

charge the same at all times (measured in volts). ??????????????? Results? ??????????????? Distance (cm)??????? Resistance (ohms)10??????????? ??????????????? 0.25 20??????????? ??????????????? 0.46 30??????????? ??????????????? 0.65 40??????????? ??????????????? 0.87 50??????????? ??????????????? 0.04 60??????????? ??????????????? 0.28 70??????????? ??????????????? 0.49 80??????????? ??????????????? 0.62 90??????????? ??????????????? 0.85 100????????? ??????????????? 0.04 ??????????????? ConclusionMy prediction was

correct, the longer the wire the higher the resistance. This happened because

when the wire was shorter the electrons had less to travel and therefore didn?t

take as long to give a reading of volts and amps. Also when the wire is shorter

the electrons move quicker because they don?t have as many atoms to push

themselves through.EvaluationTo make my experiment

more accurate I could have got 3 sets of results and found an average but this

would be too time consuming. I don?t think I could improve the experiment

because it worked very well and got me some accurate results. I also found the

experiment quite easy to set up as well. A further experiment I could do would

be to see whether the diameter of a wire effects the resistance. This would be

very fascinating because it is similar to the experiment I have done.