1st year of post-compulsory secondary education
Electric current
J.L. San Emeterio
EC Unit
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CONCLUSIONS ABOUT THE CONCEPT OF THE CIRCUIT

In the same way that water can circulate between two tanks  with different levels of water; the electric charge between two points with different potential, joined by a conductor can also circulate.                                                                                                                                                                    

The current measures the charge that flows each second. Its unit is the ampere. The device which measures it is called an ammeter. The ammeter is connected to the circuit in series.
The potential difference between two points in the circuit is measured in volts . The device which measures it is called a voltmeter. The volmeter is connected to the circuit in parallel.
The opposition of the conductor to the flow of the current is called resistance. It is measured in ohms. Its value is expressed as R= k·l /S where l is the length of the conductor, S is its cross sectional area and K (resistivity) is a coefficient which depends on the material.
El concepto de circuito
El símil hidráulico
Elementos del circuito
Magnitudes características
Conclusiones
Leyes y magnitudes fundamentales
Ley de Ohm
Potencia y energía en el circuito
Generalización de las leyes
Conclusiones
Circuitos más complejos
Asociación de resistencias
Asociación de generadores
Un circuito mixto
Conclusiones
Evaluación