CONTENTS
Electromagnetism 5
The electromagnet 12
Meters 18
The electric motor and dynamo 28
The transformer 33
Communication 43
The electrical system of the motorcar 56

This book is one in the series of Physics background books
intended primarily for use with the N uffield O-level Physics
Project. Most of the team of writers who have contributed
to the series were associated with that project. It was
always intended that the Nuffield teachers' materials
should be accompanied by background books for pupils
to read, and a number of such books is being produced
under the Foundation's auspices. This series is intended
as a supplement to the Nuffield materials - not books
giving the answers to all the investigations pupils will be
doing in the laboratory, certainly not textbooks in the con-
ventional sense, but books, easy to read and copiously
illustrated, which show how the principles studied in
school are applied in the outside world.
The books are such that they can be used with con-
ventional courses as well as with the new programmes.
Whatever course the pupils are following, they often need
straightforward books to help clarify their knowledge,
sometimes to help them catch up on any topic they have
missed in their school course. It is hoped that this series
will meet that need.
This background series will provide suitable material for
reading in homework. This volume is divided into sections,
and a teacher may feel that one section at a time is suitable
for each homework session.
This particular book is written as a background book
for the electromagnetism in Year III of the Nuffield course,
though it should be useful for pupils studying later years
to remind them of earlier work. It presupposes a know-
ledge of the work on electric currents done in Year II of
the Nuffield course and for which there is a separate back-
ground book in this series - Electric Currents.