PREFACE TO THE FOURTH EDITION

The general response to the third edition of the book was very encouraging. The authors feel that their work has been amply rewarded and wish to express deep sense of gratitude to the large number of readers who have used it, and in particular, to those of them who have sent helpful suggestions from time to time for the improvement of the book.

In the present edition, authors have made sincere efforts to make the book up-to-date. A noteable feature is the inclusion of nine chapters on Basic Electronics. It is hoped that this edition will serve the readers in a more useful way.