Current, circuits and resistance

Different kind of electronic devices broadcast sounds, display images, takes measurements, record and “remembers” information, perform calculations and regulate other devices. Electronics is the science and technology of the motion of electrons in gas, vacuum, or in any semiconductor. A device is called electronic if it is comprised of parts where the movement of tiny particles (electrons) generate electricity directly controlled by electric or magnetic fields. In electronic devices a power forms to control another. For example, in a computer the changes that occur when you press the buttons regulate the data written on the hard disk. Electricity in this way allows quick and inexpensive implementation of complex functions. Everyone today is exposed to electronic and circuit devices, so it’s important to gain the basic knowledge of electronics, electricity and circuits. If you are interested to learn some basic electronics keep reading the following information guide.

DC & AC current

Electricity is the movement of electrical charges directed along an electrified conductor.
The amperage is time dependent. Thus, there are two kinds of electricity, direct current (DC) and alternating (AC).

DC is defined as the constant flow of electrons in the same direction, for example in a cable. DC can also be considered as the current, which varies the price and not the polarity over time. This feature separates DC from AC.
The alternating current is the electric current where both the intensity and the direction changing periodically. Unlike direct current, alternating current is transmitted easily and with low cost. Fewer losses arising during transportation which can be done with thinner wires. The alternating current is considered dominant over DC because of the possibility of converting the voltage to lower or higher prices.

Electronic Circuit

An electrical circuit is called a closed electrical circuit if electric current flows through it. Observe a battery, the lamp or any other electrical device. You will find that each such device has two edges those two poles. If you connect the cable ends of a battery with the ends of a light bulb, you will notice that the lamp illuminates. Inside the cable and the lamp electrons move in the direction from negative towards the positive terminal of the battery. In addition are moving into the battery in the direction of the positive to the negative pole. Namely electrons follow a closed path. In this case we say that we have a closed electrical circuit.

An open circuit is when we stop the flow of electrical current to the circuit. Try to disconnect the wire by one pole of the battery or from one end of the lamp. We observe that the lamp goes out. This is because between the free end of the wire and the battery pole or terminal of the lamp interposed air which is an insulator. The electrons cannot move within it consistently and their movement within the bulb the battery stops. Thus, the electrical circuit is called an open circuit.


From physics it is known that the property of a body to restrict the flow of electrical current through the electrical resistance is called. The resistance is denoted by the letter R (Resistance).
In order to understand the electrical resistance in depth you can check out the correlation between electrical and hydraulic systems.