Applied Science AQA/Resistivity Portfolio

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Syllabus Content[edit | edit source]

Materials scientists need to be able to recommend appropriate materials for electrical components in a huge range of products.

In completing investigations, learners will develop their knowledge and understanding of the following concepts:

•    the meaning of resistivity

•    how the resistance of an electrical component relates to the resistivity of the material it is made from

•    importance of knowing the resistivity of a material

•    uses of materials with both high and low values of resistivity, including, for example, new semiconductors used in electronic circuits

•    use of standard procedure to measure the resistivity of a piece of wire

•    accuracy and reliability of data, recorded with appropriate precision

•    methods used in industry

•    recording appropriate measurements:

•    calculate a value for the wire’s resistivity

•    calculate the theoretical percentage error

•    calculated value compared with researched value for resistivity of the wire’s material

• reasons for differences between theoretical and calculated values

•    evaluation of methodology.

The Brief[edit | edit source]

criteria for resistivity portfolio

Advice[edit | edit source]

DON'T just copy and paste anything! You can't get any marks for something someone else wrote.

Use the official glossary to clarify the meanings of the words accurate and precise.

Checklist - before you hand in:[edit | edit source]

Have you:

Pass[edit | edit source]

  • Given a definition of resistivity
  • Explained the differences in behaviour between materials with a high and a low resistivity, using examples
  • Carried out the experiment and found a value for resistivity - with units (probably from a graph gradient)
  • Written a full risk assessment

Merit[edit | edit source]

  • Chosen examples of materials with high and low resistivities and explained why these materials are used for particular purposes in industry
  • Compared the value from your resistivity experiment with an official value - evaluated and explained why yours is different.

Distinction[edit | edit source]

  • Written about industrial methods for finding resistivity- and explained how they are both more accurate and more precise than your classroom method - e.g. the conditions in which they are carried out