Electricity - whether obtained from generators fueled by diesel oil, gasoline or coal, or hydro power created by water rushing through dynamos at hydro electric dams provides for a host of servants that we take for granted. Electricity lights out houses, heats and cools our homes and offices, does our work via vacuum cleaners and electronic calculators - computers, as well as provide entertainment via plasma and LCD TVs and iPod mp3 players. We communicate over phones - whether cellular or land line telephone and some of us are even transported by electrical hybrid cars. Yet we generally take electricity and electrical services and products all for granted on an everyday and ongoing basis.
A high resistance short is another type of short circuit. Typically , this fault occurs inside an appliance that through wear of breakage , a part of the circuit board touches a metal part- for example the metal housing or a motor part. Thus a secondary path is formed for current flow. This type of short is also called a "ground" because current is diverted out of the circuit. The ground does not lead to earth , however but to a metal part of the appliance - milk, meat and vegetables come from. None of us - or few- ever think of the origin of our meals - A short circuit is a fault that exists when there is a path for current flow other than the normal path through the appliance. For example in a room heater , a short circuit could occur because of wear or broken insulation. Two conductors in a line cord could touch resulting in high current flow that can cause a fuse or circuit breaker to "blow". That is other than the power company to whom we pay our monthly utility bills to.
The current and electrical power that is delivered over the lines to our homes and offices is delivered directly from the dynamos of your local power utilities. However even then for most the source of most of their power is simply the socket or wall receptacle into which their daily appliances are plugged or hard wired into.
Three terms that all are common to electrical appliances that we should all be familiar with as they are an integral part of any electrical system and electrical circuits which power the unspoken servants of our lives.
Switches in home and office factory floor appliances and robots control current flow by introducing a high resistance ( air or electronic gap) to start current flowing or not flowing at any point in time. Some appliances ( electric grills for example) have no separate switch. The appliance is turned on and generally inserting or removing the plug into the socket. Any device ( a lamp , a radio or washing machine) , that uses electrical energy to perform some work is a load. The load , or loads , unlike conductors, offer considerable resistance to current flow. Thus high electrical resistance makes it possible for any electronic or electrical appliance to convert electrical energy to another form of energy - light sound or mechanical movement. All to provide work and to be a personal servant to you and your family at home or at your office or factory floor. Imagine the stifling heat in the summer with an air-conditioning failure or a home of frozen pipes in a cold January Northern Minnesota or Canadian winter - Winnipeg in January 40 below zero both Fahrenheit and Celsius. How would you be able to see in the dark - It would be sheer dark without light bulbs or florescent lighting. It would be back to coal oil lamps!