Covers the physical processes and information needed for Key Stage 3 of the National Curriculum and shows the effect of physics on everyday lives. This title includes coverage of Key Stage 3 Programmes of Study and Common Entrance requirements; foundation for GCSE with material up to Level 8; and questions and activities.A relay is an electrically controlled switch. It uses a small current to turn on a separate circuit, which may carry a large current. The diagram shows a relay to turn on the starter motor of a car. On starting, a very large current flows through theanbsp;...
|Author||:||George Bethell, David Coppock|
|Publisher||:||Open University Press - 1999|