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.