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.
Rays used in the medical field to kill cancer cells and make pictures of the brain, and in industrial situations as an inspection tool. These rays have the highest frequencies and the most energy of electromagnetic waves.