Publisher's Synopsis
Excerpt from The World Book, Vol. 4 of 10: Organized Knowledge in Story and Picture
A coil with an electric current ?owing through it acts like a magnet. The coil has a north and a south magnetic pole, as has a bar magnet; it retains its magnetic force only so long as the current ?ows. If the direction of the current is reversed the polarity of the coil is reversed. If an iron core is placed in the coil the magnetic strength is increased (see electromagnet).
About the Publisher
Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com
This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.
