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!
So that we can use the computer, watch the television and fans. And other things that need electricity. Electromagnets are used in electrical devices like electric fan, motor, door-bell, electric buzzers, washing machines, etc., whenever strong magnetic fields are needed to be pâ¦roduced, electromagnets are used. These are used in electrically operated relay switches, and in nuclear research laboratories for directing charged particles.
Copper is used a lot because it will also absorb magnetic energy as well as radio waves. Most thin amounts of non-conductive materials (paper, cotton, rubber) will not affect Rf waves, but the thicker the material, the more chance it has to actually absorb the radio wave energy (and therefore block it). One reason why mountains, tunnels and deep bridges play havoc on radio reception, especially AM radio.