• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The aim of this investigation is to find out how the resistance of a wire is affected by its lengths. I will do this by changing its lengths and working out each lengths potential difference and current.

Extracts from this document...

Introduction

EXPERIMENT TO FIND THE AFFECT THAT THE LENGTH OF A WIRE HAS ON ITS RESISTANCE

Introduction

The aim of this investigation is to find out how the resistance of a wire is affected by its lengths. I will do this by changing its lengths and working out each lengths potential difference and current. The reason that I am measuring the potential difference and the current of the circuit is because the formula for resistance is.

image00.png  or  image00.png  or  image03.png 
(resistance= ohms (
Ω), potential difference= volts (V), current= amperes (A))

Electricity is the movement of charged electrons inside an insulator and it is also a form of energy. The constant variables in this experiment will be:

  • The temperature: the hotter the inside of a metal the more active the electrons are and the more collisions they will make with the walls of the wires making it harder for the current to pass though
  • The material of the wire: different metals have different resistances and will give you unreliable results
  • The thickness of the wire: the thinner the wires are the less current can pass through it at one time.

The independent variable will be the length of the wires as we are trying to find out its affects on the resistance. The independent variable affects the dependant variable as in that when you change the independent variable the value of the dependant variable will change. The dependant variable in this case would be the resistance of the wires and it will change as the length of the wire changes.

Hypothesis: I think that the resistance of the wire will be higher when it is longer. This is because the electrons have further to travel than inside the smaller wires so it is harder for them. Therefore the electrons will use up the energy they obtained from the power source quicker and lowering the potential difference.

Method

Apparatus:

  • Nichrome (nickel-chromium alloy) resistant wires with changeable lengths
  • At least 5 conducting wires- to connect all the components
  • Voltmeter- to measure the potential difference
  • Ammeter- to measure the current
  • 2V battery- to provide sufficient voltage to push the electrons around the circuit. Converts AC to DC and steps it down to 2V from 230V
  • Access to mains electricity-to power the power source
...read more.

Middle

image10.png
1st

Length(cm)

Potential Difference (V)

Current (A)

Resistance (Ω)

10

0.469

0.25

1.88

20

0.631

0.16

3.94

30

0.973

0.09

 10.81

40

0.631

0.08

7.89

50

0.701

0.07

10.01

60

0.623

0.06

10.38

2nd

Length(cm)

Potential Difference (V)

Current (A)

Resistance

10

0.515

0.28

1.84

20

0.611

0.16

3.82

30

0.662

0.11

6.02

40

0.662

0.08

8.28

50

0.707

0.07

10.10

60

0.717

0.06

11.95

3rd

Length(cm)

...read more.

Conclusion

Conclusion

My hypothesis was proved true by my investigation as the resistance increased with the length of the wire. This means that the electrons found it harder to travel across longer lengths therefore needing more voltage to push it along. This means there is an increase in voltage and decrease in the current. The resistance equation mans that the resistance will keep getting higher with the length of the wire.

Evaluation

If I were to do this experiment again I would change a few aspects of it in order to obtain more reliable results and to make it a fairer test. I would keep the current the same although out the experiment by using a rheostat and adjusting the current to the same before every measurement is taken. I would keep the temperature of the room the same so that it does not have any effect on the electrons or the conducting wires. This will make it’s a fairer test because then you are only having one dependant variable which will make the outcome of the dependant variable more reliable.

...read more.

This student written piece of work is one of many that can be found in our GCSE Electricity and Magnetism section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Electricity and Magnetism essays

  1. Investigate the resistance of different wires and how at different lengths the voltage increases ...

    Using the variable resister I will keep the current 0.3. 4) I will them do the same test with the copper wire at different lengths (20, 30, 40, 50, 60, 80 and 100) by doing this I can acquire a series of results 2 contrast and compare which will den result in a more accurate end result.

  2. An experiment to find the resistivity of nichrome

    These collisions slow down the flow of electrons causing resistance. Resistance is a measure of how hard it is to move the electrons through the wire. Factors 1.Temperature : If the wire is heated up the atoms in the wire will start to vibrate because of their increase in energy.

  1. Resistance and Wires

    Turn on the power pack and record the current from the ammeter and the voltage from the voltmeter. 6. Turn off the power pack. 7. Repeat this process for all the diameters of wires. 8. Work out the resistance for all the results using Ohm's law.

  2. To find out what happens to the efficiency of a motor as I change ...

    We made sure not to swap these people around because maintaining the accuracy of our results relied upon both the reaction time and hand-to-eye coordination of these two people. Changing them around would have meant using people with different reaction times, so the test would have been unfair.

  1. The aim of this experiment is to investigate how a change in the length ...

    After that I connected a fifth wire from the variable resistor to the nichrome wire at the 100cm mark: Lastly I connected the sixth wire from the variable resistor to the negative terminal of the battery, 'tuned' the variable resistor to the required voltage, and jotted down the reading on the ammeter in a table.

  2. Free essay

    Resistance Investigation. My aim in this investigation is to measure the amount of resistance ...

    However if the material of the wire is and alloy then the resistant of the electrons would certainly increase, as the second metal contaminating the first metal would allow more contact between the electrons and the atoms of the first and the second element, which increase the resistance and decrease the flow of the current.

  1. To find out if and why wire lengths give resistance - To find out ...

    It must be wooden because it is an insulator and reduces the risk of being electrocuted Method: Collect together the apparatus as shown in the apparatus list above and set it up as shown in the following diagram: Have the rest of the equipment on stand-by.

  2. Objective: to investigate how the rate of resistance is affected by the different thicknesses ...

    For example mercury is a Superconductor. In order for mercury to become a superconductor it has to be cooled at 4.15K, -269oc. Prediction I predict from that, from gathering all my information from my scientific theory that, firstly as I increase the length of the wire, resistance will also increase.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work