Electric Current and It’s Field

Electric current possess electrical property associated with each point in space when a charge exists in any form. The size and direction of the electric field are represented by the value of E, called electric field strength or electric field strength or simply electric field.

CONTENT

ELECTRIC CURRENT

POTENTIAL DIFFERENCE

ELECTROMOTIVE FORCE

SOURCES OF ELECTRIC CURRENT

OHM’S LAW

 

ELECTRIC CURRENT

An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate at which the charge flows through the surface or into the control volume. In a circuit, a charge carrier is usually an electron that moves through a wire. In semiconductors, they can be electrons or holes. In the electrolyte, the charge carrier is an ion, while in the plasma, the ionized gas is an ion and an electron.

The SI UNIT of CURRENT is AMPERES, or AMPERES, where electric charges flow on the surface at a rate of ONE COULOMB per second. Amperes (symbol: A) are SI basic units: 15 Measure current using a device called an ammeter. The current in gases and liquids usually consists of positive ion flow in one direction and negative ion flow in the opposite direction. In order to deal with the overall effect of the current, its direction is usually considered to be the direction of the positive charge carrier.

Electric field

The current of a negative charge moving in the opposite direction is equivalent to a positive charge of the same size moving in a conventional direction, and must be included as a contribution to the total current. The current in the semiconductor consists of the movement of holes in the conventional direction and the movement of electrons in the opposite direction. There are many other types of currents, such as charged particles and mesons in proton beams, positrons, or particle accelerators.

The current generates an accompanying magnetic field, such as an electromagnet. When the current flows in an external magnetic field, it experiences magnetic force like a motor. The heat loss or energy dissipation of the current in the conductor is proportional to the square of the current.

POTENTIAL DIFFERENCE

Potential difference refers to the energy difference between the two points of the charge carrier in the circuit. In volts: potential difference (p. d.) Measured in volts (V), also known as voltage. When the charge carriers pass through them, the energy is transferred to the electrical components in the circuit. We use a voltmeter to measure the potential difference (or voltage).

Potential difference formula: V=I x R

The potential difference (the same as the voltage)is equal to the amount of current multiplied by the resistance. When the charge flows between two points in the circuit, the potential difference of one volt is equal to the energy of one joule used by the charge of one coulomb.

ELECTROMOTIVE FORCE

Electromotive force, abbreviated E or emf,the energy per unit charge, is given by an energy source, such as an electric generator or battery. Energy is converted from one form to another in a generator or battery because the device works on the charge transmitted inside itself. One terminal of the device becomes positively charged,and the other becomes negatively charged. The work done on a unit charge, or the energy obtained per unit charge, is the electromotive force. Electromotive force is the characteristic of any energy source that can drive the charge around the circuit. It is abbreviated as E in the international metric system, but it is also commonly known as emf.

 

e.m.f (E) =   work  = W

charge    Q

Note V = W therefore W = QV

Q

 

Despite its name, electromotive force is not actually a force. It is usually measured in volts, which is equivalent to one joule per coulomb charge in a meter–kilogram–second system. In the electrostatic unit of the centimeter-gram-second system, the unit of electromotive force is stat volt, or one erg per unit of electrostatic charge.

SOURCES OF ELECTRIC CURRENT

An electrical network is the interconnection of electrical components such as resistors, inductors, capacitors, transmission lines, voltage sources, current sources, and switches.

1.  Electricity through friction

The first observations on electrical phenomena were made in ancient Greece. This happened when the philosopher Thales of Miletus (640-546 BC) discovered that when amber strips were rubbed by tanned skin, they produced attractive features that were not previously available. When we use our clothes to wipe the pen, we will produce static electricity. The same happens when we rub a piece of glass with silk or amber and wool

2. Chemical action of electricity

All batteries consist of electrolytes (which can be liquid, solid or semi-solid), positive and negative electrodes. Electrolytes are ionic conductors. One of the electrodes generates electrons, and the other receives them. When the electrodes are connected to the circuit to be fed, they generate current. Once the chemical energy is converted into electrical energy, the battery where the chemical substance cannot restore its original form is called a primary battery or a voltaic battery.

3. Electricity under the action of light

As sunlight becomes more intense, the voltage generated between the two layers of photovoltaic cells increases. But how does a photovoltaic cell work? In the absence of light, the system does not generate energy. When sunlight hits the plate, the cells begin to work. The photons of sunlight interact with the available electrons and increase their energy levels. In this way, electricity is generated through solar energy.

4. Thermoelectric effect

Thermal power generation equipment is a device that uses a turbine powered by steam under pressure to move the axis of the generator. Conventional thermal power plants and nuclear power plants use the energy contained in pressurized steam. The simplest example is to connect a kettle filled with boiling water to a paddle wheel, which in turn is connected to a generator. The steam jet from the kettle moves the rotor. Therefore, we can obtain steam in a variety of ways, such as by burning coal, oil, natural gas, urban waste, or using a lot of heat generated by nuclear fission reactions. You can even generate steam by concentrating the energy of the sun.

5. Electricity generated by pressure

The pressure exerted by the groundwater flow is the process by which large ships are used as an alternative energy source for the main system. In dams, electricity is generated by forcing pipes to release controlled high-pressure water flow. Water drives the turbine to move the generator, which generates current. Then, this high and low voltage current passes through the voltage booster and converts it into electricity.

6. Hydraulic power through the action of water

Of all the ways used to generate energy listed above, magnetic energy is most commonly used to generate a large amount of electricity. It is based on the fact that when the conductor is moved in the presence of a magnet, the orderly movement of electrons in the conductor will occur. This is due to the attraction and repulsive force caused by the magnetic field. The operation of alternators, motors and generators is based on this form of power production.

OHM’S LAW

Ohm’s law states that the current passing through the conductor between the two points is proportional to the potential difference between the two points. Introduce a proportional constant, resistance, [11]one that reaches the usual mathematical formula that describes this relationship.

 I=V/R

where I is the current through the conductor, in amperes, V is the potential difference measured across the conductor, in volts, and R is the resistance of the conductor, in ohms. More specifically, Ohm’s law states that R in this relationship is constant and has nothing to do with current.

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