Definition of electric current
The movement of electric charge is known as an electric current, the intensity of which is usually measured in amperes. Current can consist of any moving charged particles; most commonly these are electrons, but any charge in motion constitutes a current.
By historical convention, a positive current is defined as having the same direction of flow as any positive charge it contains, or to flow from the most positive part of a circuit to the most negative part. Current defined in this manner is called conventional current. The motion of negatively charged electrons around an electric circuit, one of the most familiar forms of current, is thus deemed positive in the opposite direction to that of the electrons. However, depending on the conditions, an electric current can consist of a flow of charged particles in either direction, or even in both directions at once. The positive-to-negative convention is widely used to simplify this situation.
Work on the road
Undoubtedly, one of the most interesting uses of electricity in everyday life is a traffic light. There are even special systems that allow long phase justification of the amount of light waiting to drive through the intersection cars. This is a very interesting solution, but it also can be subject to failure. Then it is necessary to help electricians to solve problems, and control traffic can be much more difficult than the use of traffic lights. Electricity can make the traffic jams formed especially in large cities are less burdensome for enjoying the busy streets of people. However, you need time to time to monitor these intelligent systems to ensure their trouble-free operation.
Electricians in Canada
Training of electricians follows an apprenticeship model, taking four or five years to progress to fully qualified journeyman level. Typical apprenticeship programs consists of 80-90% hands-on work under the supervision of journeymen and 10-20% classroom training. Training and licensing of electricians is regulated by each province, however professional licenses are valid throughout Canada under Agreement on Internal Trade. An endorsement under the Red Seal Program provides additional competency assurance to industry standards. In order for individuals to become a licensed electricians, they need to have 6000 hours of practical, on the job training. They also need to attend school for 4 years and pass a provincial exam. This training enables them to become journeyman electricians. Furthermore, in British Columbia, an individual can go a step beyond that and become a ?FSR?, or field safety representative. This credential gives the ability to become a licensed electrical contractor and to pull permits. The various levels of field safety representatives are A,B and C. The only difference between each class is that they are able to do increasingly higher voltage and current work.
Restricted electrical licenses are also issued for specializations such as motor winder, appliance repair, audio/visual installation and HVAC installation.