CDs reproduce 44,100 samples per second. Which has a maximum frequency reproduction of 22,050 Hz, or just a hair past the upper limit of human hearing. In this way CDs can theoretically reproduce any frequency in the human hearing range.
5. Which motor is NOT suitable for use as a DC machine?
Neon lighting runs at a high voltage, typically above 1000 Volts. A fireman's switch protects a fireman from receiving a shock when a water jet is sprayed onto the installation. The switches are red, and mounted in a conspicuous position. (This is specified by IEE Regulations (Europe), SANS (South Africa), UK Electricity regulations and many Asian countries. I am unable to confirm other countries' requirements, so feel free to let me know.)
9. What do we call a collection of two or more computers that are located within a limited distance of each other and that are connected to each other directly or indirectly?
Extension cords can be a tripping hazard, and can be easily damaged, causing an unsafe situation. There are many ways of safely getting power to each work place, where wiring is protected and concealed.