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

To investigate the resistance of different materials in the form of wirer, resistors and other materials.

Extracts from this document...

Introduction

Ohms Law Planning A: Aim: To investigate the resistance of different materials in the form of wirer, resistors and other materials. Hypothesis: The shape, the thickness, the length of the resistor and the material that makes up the resistor itself will affect the electric conduction capability (resistance). Electrons can create a current, so the more free electrons there are, the more conducting capability that material has that is why metals conduct. Materials with wider diameter have more free electrons because the surface area is bigger compared to length so more electrons are free per cm as example. So if a cable is bigger in diameter it should have less resistance. Resistance will also increase as the length of the wire increases because electrons will be slowed down while traveling. ...read more.

Middle

* Resistor Method: * Connect the wires to the circuit by the crocodile clips * Take the voltage and current readings from the meters * Increase/decrease the supply from the power pack and take the readings again * Repeat the experiment with different materials, wires, bulbs, resistors Results: Wire: Setting Volt Actual Volt Ampere Milliampere Resistance Ohms 2,00 1,80 0,100 100,00 18,00 4,00 3,50 0,200 200,00 17,50 6,00 5,50 0,300 300,00 18,33 8,00 7,50 0,420 420,00 17,86 10,00 9,30 0,520 520,00 17,88 12,00 11,40 0,600 600,00 19,00 Average: 18,10 ? Bulb (variable resistor used): Actual V Ampere Milliampere Resistance Ohms 1,40 0,12 120,00 11,67 1,70 0,14 140,00 12,14 1,80 0,14 140,00 12,86 2,60 0,15 150,00 17,33 3,50 0,16 160,00 21,88 4,40 0,18 180,00 24,44 5,50 0,28 280,00 19,64 7,50 0,32 320,00 23,44 Average: 17,92? ...read more.

Conclusion

Here the current and voltage are not proportional. The bulb obviously gets hotter and hotter. Since "resistance" is measured by the gradient of the graph, we have here an example where the resistance is increasing. But obviously we are dealing with "normal" resistors in this investigation, so the gradient of the graphs obtained should be the same throughout linear and the resistance should remain constant as the voltage/current is changed. Evaluation: * To get better results the following things should be done: * The power supply should be varied smoothly between 0-12V with 0.1V interval so more averaged results can be taken. * Temperature has to be absolute constant to create a fair test. Otherwise Ohms law will not apply. * Better quality equipments should be used. * More accurate Meters Philipp C. Protschka Page 1 of 6 1 May 2007 Physics Practical Last printed 12/3/2002 12:16 AM ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal Physics 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 AS and A Level Electrical & Thermal Physics essays

  1. To Investigate How the Resistance of the Light Dependent Resistor Depends On the Current ...

    In the Analysis and the graph I have shown two main anomalous points, this means that there must have been a slight error in my experiment. Although the graph is overall accurate and the results precise it is easy to see, the anomalous averages plotted because they do not all lie along the same best-fit line.

  2. Investigating how temperature affects the resistance in a wire

    -One digital multi-meter with an internal 9V supply (used to measure the ohms) -Tap water (used to create a water bath) -A kettle (used to heat the water for temperatures (for the experiment) that were above room temperature to be used in the water bath)

  1. Investigating the effect of 'length' on the resistance of a wire

    I also made sure that I carried out the experiment in a safe way and abiding by the safety precautions mentioned in the planning phase. The Results are on the next page... The Results: The first set of results is shown in the table below: Constantan wire (diameter of 0.11mm)

  2. Find The Internal Resistance Of A Power Supply

    equipment which could damage the circuit and cause the fuse to blow. The work surface will be cleared of clutter before beginning experiment to make sure that the equipment is stable. When connecting and disconnecting equipment, I will turn of the power pack to avoid electrocution.

  1. Resistor - What do resistors do?

    The resistive coating is spiralled away in an automatic machine until the resistance between the two ends of the rod is as close as possible to the correct value. Metal leads and end caps are added, the resistor is covered with an insulating coating and finally painted with coloured bands to indicate the resistor value.

  2. To investigate the factors which may affect the resistance of resistance putty.

    Potential Difference = Resistance) I Current flowing The P.d. is always measured in Volts (V), current flowing in amperes (A) and resistance in ohms (?). Along with Ohm's law there is also Kirchoff's current and voltage laws. In Kirchoff's current law, he states that the electric current in amperes, which flows into any junction

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