Final answer:
Low-voltage switching is safer due to the decreased risk of electrical shocks and fires as it avoids large sparks and simpler safety devices can be used. AC power further enhances safety with its natural zero-crossing points. Homes use lower voltages for safety, while high voltages in transmission lines reduce power losses.
Step-by-step explanation:
Low-voltage switching is considered safer than line voltage switching because it significantly reduces the risk of electrical shock and fire hazard. When a circuit breaker or switch operates at a high voltage, interrupting the flow of electricity can cause a spark that may ionize the air and allow current to continue flowing. By contrast, low-voltage systems don't generate large or dangerous sparks, making them much safer for use in areas where sparking could pose a risk, such as in close proximity to flammable materials or in medical settings with microshock-sensitive patients.
In addition, high-voltage systems require complex safety mechanisms, such as insulating gas and jets of gas to extinguish sparks. Conversely, fuses and circuit breakers designed for low-voltage applications are simpler to produce and manage. Furthermore, the prevalence of AC power allows for safer operation due to the natural zero-crossing points in the current cycle which offer opportunities to interrupt electrical flow and extinguish arcs.
Why High Voltage for Transmission Lines
Transmission lines operate at very high voltages to minimize power losses during long-distance transport of electricity. Transformers are used to step up the voltage for transmission and step it down for safe household use. Lower voltages are utilized in household circuits to ensure electrical safety and simplicity in protection devices.