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

Planning an investigation

Extracts from this document...

Introduction

Planning an investigation Obtaining Evidence For my investigation I wired several different wire all with different properties and width of wire to collect results for different resistance in wires. The three different types of wire I used were Constantan 28 wire Constantane32 and copper wire 28. Each wire was subjected to 2 volts at various different lengths of the wire. I measured the voltage and amperes every 10-center meter down a meter long length of wire. 28 Constantan wires are o.40mm in diameter and Constantan 32 was 0.28mm in diameter, which is 1/4 smaller then 28 I got this information from a secondary source Philip Harris Catalog. I turn I wired up each wire as 100cm subjected it to two volts then measured the amperes and voltage. The results I've obtained show slight internal resistance as the current increases but this difference we assume is negligible we can safely ignore this factor. ...read more.

Middle

0.17 1.00 0.17 80.00 0.21 1.50 0.14 80.00 0.16 1.10 0.15 70.00 0.20 1.60 0.13 70.00 0.15 1.10 0.14 60.00 0.19 1.70 0.11 60.00 0.14 1.20 0.12 50.00 0.19 1.70 0.11 50.00 0.13 1.20 0.11 40.00 0.14 1.80 0.08 40.00 0.11 1.30 0.08 30.00 0.11 1.90 0.06 30.00 0.09 1.30 0.07 20.00 0.10 2.00 0.05 20.00 0.07 1.30 0.05 10.00 0.06 2.10 0.03 10.00 0.03 1.40 0.02 Constantan 32 1 Constantan 32 2 Length of wire (cm) V in volts I in amps R is ohms Length of wire (cm) V in volts I in amps R is ohms 100.00 0.69 0.06 11.50 100.00 0.72 0.04 18.00 90.00 0.68 0.06 11.33 90.00 0.69 0.04 17.25 80.00 0.67 0.06 11.17 80.00 0.68 0.05 13.60 70.00 0.66 0.08 8.25 70.00 0.67 0.07 9.57 60.00 0.65 0.08 8.13 60.00 0.66 0.09 7.33 50.00 0.63 0.10 6.30 50.00 0.65 0.10 6.50 40.00 0.60 0.12 5.00 40.00 0.62 0.12 5.17 30.00 0.58 0.16 3.63 30.00 0.61 0.18 3.39 20.00 0.58 0.20 2.90 20.00 0.50 0.21 2.38 10.00 0.43 0.32 1.34 10.00 0.47 0.41 1.15 Constantan 28 1 Constantan 28 2 Length of wire (cm) ...read more.

Conclusion

We can prove that Ohms law works by looking at Constantan wire. 50cm = 6.30 ohms 100cm = 11.50 ohms This shows that Constantan wire when doubled in length will double in resistance. Evaluation My prediction that when doubling the length of the wire the resistance would double also was in the Constantan wire true, therefore we can assume it follows ohms law. The copper wire seamed to follow ohms law until we got to the shorter lengths of wire were the length of wire was sufficient to heat up and disorientate the graph, Thus from this we can see that copper doesn't obey Ohms law. The double the length the double resistant could be interpreted into the more wire mass the current flows in the more resistance, If this is so if you doubled the diameter you should double the resistance as well. I'm undecided whether my results would be different for the Constantan wire if we used a longer wire strip and a increased voltage we may have had a different story. ...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. Marked by a teacher

    Investigate young's modulus behind Constantan and Copper.

    4 star(s)

    I have worked out the cross sectional area as the same in the procedure before. Here are my results for constantan: Diameter: 0.35x10-3 Area: p r^2:9.6210x10-8 m2 Here are my results stated above showing the results from the constantan wire.

  2. Resistance of a Wire Investigation

    Plant- Different species plants have different photosynthetic rates due to the different leaf structures of the plants. Even plants of the same species may have slightly different rates of photosynthesis since there may be more or less chlorophyll in the leaves to absorb light.

  1. Ohms Law.

    To collect the data for my graph I have chosen to take a range 20 of lengths. I have chosen a range of 20 as to plot an accurate graph, I will need at 20 points to mark on the graph if I want to make precise and reliable results, to see if there are any patterns and trends.

  2. The elasticity of copper investigation

    (m) Rearranging: 2Ep / F = ?x This means we can work out the extension another way and see how much energy there is in the copper wire. Apparatus * G-clamp: to hold down the wire on the wooden block * 2 metre rulers in mm: to measure the

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