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

Resistance coursework

Extracts from this document...


Resistance coursework Sneha Patel 11'O Aim: To investigate how the resistance of a piece of resistance wire depends on length and to find the length of wire needed to make the required resistance. Prediction: I predict that when you increase the length of the resistance wire the resistance will increase. I am predicting that this will occur because of the preliminary investigation where we found that in a series circuit resistance wires put together produce a higher resistance. This is in fact the same as making one long resistance wire. In a series circuit if you add resistors then the resistance increases this is like you are increasing the length. I predicting that when the length doubles the resistance will double. As the length increases the resistance increases because there are more positive ions in the resistance wire for the negatively charged electrons to hit. It takes longer because as the electrons move around the circuit they get energy at the power supply this in creases there energy and they move to the resistance wire were they hit the positive particles, if the wire is longer there will be more particles to hit and vice versa, if the length is short there will be less particles to be hit. Therefore the resistance will increase when the length is longer and decrease when it is shorter Preliminary experiment: In this experiment we used constantan wire to keep the test fair. ...read more.


Reliability: To make the experiment and investigation reliable we will be repeating it twice this will give us an accurate result and also we will gain an average, we also be taking a range of lengths going up in 20 cm to ensure accurate results again. Hopefully we will be able to take 7 or 8 different lengths in total. Sneha 11'O Accuracy: To be accurate in this experiment we will be using a meter rule to measure the length of the wire however this may not be very accurate as the resistance wire is not straight. We will also be using a micrometer to measure the diameter of the wire to make sure the wires diameter does not change if it does change ten it will cause the resistance to go down. We will also make sure that the voltmeter and ammeter readings are accurate by making sure we are reading it from eye level however if we used digital voltmeters this could be even more accurate. Results: With the results that I collect I will make a table showing the averages of the 2 experiments and the plot a graph to show the averages of both experiments against the different lengths from this we will be able to see the relationship between the length of wire and resistance. Here is a sample of my table Results Table Length (Cm) V1 (Volts) I1 (Amps) ...read more.


There were some difficulties in the experiment as the ammeter kept moving so an accurate reading was not able to be taken also the measurement of the wire was not as accurate as we would have hoped as the wire was bent in some places which could cause the length to go up or down by a few millimetres and these millimetres could make a big difference to the resistance. There were some good qualities in the method for example because we repeated the experiment twice so we were able to gain an average meaning it could not be a bias result this made the experiment very reliable. We also used some accurate equipment like the micrometer to measure the diameter of the resistance wire we used this to make sure that it was a fair test. This is because as we know diameter affects the resistance. The readings we got were that the diameter of the wire was 0.28 cm throughout different lengths.If there were improvements to be made I would say that we could use even more detailed measurements and apparatus to create an accurate experiment. We could use the nichrome wire and use a water bath to keep the temperature different maybe we would see a different result. Also we could change the method by drawing a scatter diagram of current against voltage and using gradients find out how much resistance increases with length. ...read more.

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.

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. Rate of reaction

    This is simply because the particles carry more energy and collide more often where these collisions contain enough energy to break the energy barrier: Temperature Raised Particles, when moving faster, collide with greater power. The reaction therefore becomes faster Collisions between particles are useless unless they break the energy barrier

  2. Resistance Coursework

    An ammeter is used to measure current in Amperes. A voltmeter is used to measure the voltage (V). I will be using both of these devices in my experiment. Their symbols are shown below: Independent Variable: The length of the wire.

  1. Resistance Coursework

    Length The gradient of my graph was 2 which gave me the answer 0.2 ?/cm 10 My results show me that my prediction was correct. It tells me that as the length of the wire increases the amount of resistance increases.

  2. Physics Coursework

    and at 80�C the resistance was 8.77k?. My teacher advised that a fixed resistor between these values would give the sensor sufficient resolution at high temperature. (114.32k? + 8.77k?)/2= 61.545 k? I found a resistor close to this value (68 k?) and used this in my potential divider circuit.

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