The ammeter and measuring the electric current intensity
The electric energy is the cleanest source of energy as it does not pollute the environment , The electricity plays the important role in the daily life , It is used to light up our houses , factories , streets , It is used in operating some machines such as the radios , televisions , washing machines , irons , And the electric heaters , We can not imagine our life without the electric current .
The electric current
The electric current is generated in the electric power stations that are away from our houses by hundreds or thousands of kilometers , The electric current is the electric negative charges flow ( the electrons ) through the conducting material ( as a metal wire ) .
All the elements consists of the atoms which consist of the nucleus and the electrons , The nucleus is found in the center of the atom and it contains two types of particles which are the protons ( positively charges ) and the neutrons ( electrically neutral ) .
The electrons are very small particles which are negatively charged and they rotate around the nucleus ( due to the attraction force that is found between the electrons and the protons ) , When the attraction force is weak or vanished , The electrons will leave the atom and they will become free .
The electric connecting wires are made up of metals characterized by presence of the attraction force between its protons and its electrons , where on connecting these wires with an electric source , an electromotive force is generated and the electrons are pumped in one direction and move in the wire ( conductors ) creating the electric current .
The atom is electrically neutral because the number of the protons ( positively charged ) in the nucleus equals the number of the electrons ( negatively charged ) that rotate around the nucleus , The nucleus is positively charged because it contains the protons ( positively charged ) and the neutral neutrons .
The current intensity
The current intensity is from the physical properties of the electric current , If you pass an electric current through a circuit and the lamp light up , the intensity of light is not determined by the number of electrons , but by the rate of the flow of electrons through a specific point in the wire .
The electric current intensity is the quantity in coulomb or the electric charges flowing through a cross-section of the conductor in one second , The current flowing through the conductor at the certain time interval is directly proportional to the charge quantity .
If a quantity of charge ( q ) coulomb flows through a conductor in a time ( t ) second , The measuring unit of the current intensity is Ampere , The measuring unit of the quantity of electricity is Coulomb , And the measuring unit of the time is the second .
Electric current intensity ( I ) = Quantity of charge (q ) / Time in seconds ( t )
The ampere is the electric current intensity passing through the circuit when the charge of one coulomb passes through the given cross-section in one second , The coulomb is known as the charge transferred by the constant current of intensity one ampere in one second ,
The apparatus used in measuring the electric current intensity is called the Ammeter which is connected in series in the electric circuits , The Ammeter has the symbol A in the electric circuit , The ammeter is not connected directly to the battery , because this damages it .
Uncut electric charger device
The uncut electric charger device ( uninterruptible power supply ) ( UPS ) , It is used to store the electric energy for a long or short period of time , where , it provides the electric devices with the electric current so as to continue operating when there is no current at home .