Easyphysics

 P1: GCSE Science - EDEXCEL
Producing and Measuring Electricity
Glossary

Did you know? 

The heating effect produced by the electric current flowing in a wire is used in the back window of a car to keep it clear of water vapour.

 

      

 P1 Current - voltage graph for a fixed resistor and a filament lamp

Syllabus Summary Questions Answers

        
     1. Fixed Resistor

                                      

                      Graph of current against voltage for a fixed resistor

        Explanation

  • Current is directly proportional to voltage.

  • Gradient of graph is constant.

  • Resistance is 1/gradient.

  • Resistance is constant.

  • Resistance is constant as long as temperature of resistor is constant.

     2. Filament Lamp

                                        

                  Graph of current against voltage for a filament lamp.

        Explanation

  • Gradient gets smaller.

  • As current increases, the filament becomes hot, its atoms start to vibrate more and slows

        the flow of electrons. (Higher tier only)

  • Resistance increases.