Welcome to the Official Guide to No Safety in Numbers. A biological bomb has just been discovered in the air ducts of a busy suburban mall. At first nobody knows if it's even life threatening, but then the entire complex is quarantined, people start getting sick, supplies start running low, and there's no way out. This is the ultimate guide to the book that started the series!
Electromagnets are used in things that have moving parts, eg. CD players, heads on Hard drives, automatic doors in a grocery store, electric windows, motors etc., Some examp â¦ les include: You can slide the bolts of locks and latches, tap out telegraphic dots and dashes, open and close switches in distant electric circuits.
Radio waves and microwaves emitted by transmitting antennas are one form of electromagnetic energy. They are collectively referred to as radiofrequency or RF energy or radiation. Often the term electromagnetic field or radiofrequency field may be used to indicate the presence of electromagnetic or RF energy.