文档介绍：Reading 8 Ron Bertrand VK2DQ
ISM
There are no questions in either the NAOCP or AOCP exam about ism. You are
justified then in asking why we are doing this subject. Well, although there are not any
questions in the exam, later on in this course we do have to cover topics like:
Inductance
Mutual Inductance
Alternating Current
It is really impossible to gain an understanding of these subjects without a basic
understanding of ism. I will try to keep the topic as brief as possible bearing in mind
what has to be learnt, and more to the point 'understood' later on.
ism is a very large subject, however I will cut it down into what you really need to
know to help with your understanding of other topics later on.
I think it is a deficiency in the Amateur Radio syllabus that questions are not asked on
ism.
ISM AND ELECTRICITY
Any wire carrying a current of electrons is surrounded by an unseen area of force called a
ic field. For this reason, any study of electricity or electronics must consider
ism.
Almost everyone has had experiences with s or with passes at one time
or another. A attracts pieces of iron but has little affect on practically everything
else. Why does it single out the iron? pass, when laid on a table, swings back and
forth, ing to rest pointing toward the North Pole of the world. Why does i