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Electricity

Free online electricity lessons for elementary school,  middle school and high school.
chemistry high school
 

Science class

Chemistry

Electricity

Optics

Mechanics
Electricity lessons
Electrical components
-Two-terminal electronic components
- Basic electrical components
- Diodes
- What's a resistor ?
- How to determine a resistor value ?
- Resistors effects in circuits
- How to use a resistor ?
- Characteristic curve of a resistor

How to build simple circuits and draw diagrams
- How to build a basic electrical circuit
- How to draw diagrams of electric circuits

The electric current
- Conductors and insulators
- Direction of electric current in a circuit
- The dangers of electricity
- Current intensity - units
how to measure current ?
The Voltage
- The voltage and its units
- How to measure a voltage ?
- Voltage in open and closed circuits
- Rated current and voltage for a lamp
Alternating voltage and current
- Alternating currents effects on led
- What are alternating current and voltage ?
- Periodic alternating voltage and its properties
- Oscilloscope
- Oscillogram
- Frequency
- Measuring RMS voltage with a voltmeter
Serie circuits
- What's a serie circuit ?
- Series circuit properties
- Short circuit in  series circuit
- Current law in series - circuits
- Voltage law in series circuits
Parallel circuits
- What's a parallel circuit ?
- Some parallel circuits properties
- Short circuits in parallel circuits
- Nodes and branches in parallel circuits
- Current laws in parallel circuits
- Voltage laws in parallel circuits
Laws of electricity
- Ohm's law
- Current laws in series circuits
- Voltage laws in series circuits
- Current laws in parallel circuits
- Voltage laws in parallel circuits
Generating electricity
- Voltage for coil wires
What is an alternator ?
- Alternating currents and voltages
- Generating electricity in power plants

Electric power and energy
- Electric power and power rating
- Electric power received by an electrical device
- Electric power consumption by an electrical device
- Relationship between - Electric power and energy


The Voltage

Voltage in open and closed circuits

   
1) Voltages in a closed circuit

In a closed circuit, the electric current flows and the voltage is always:
- Different from zero for the battery or electric generator.
- Different from zero for a lamp, a motor, a resistance or a bypass diode.
- Zero for a connecting wire or a closed switch.

2) Voltages in an open circuit

In an open circuit the electric current does not flow and the tension is always:
- different from zero for a battery or an electric generator.
- Zero across a lamp, a motor, a resistor, a bypass diode or a switch closed or wire connection.
- Is equal to the Battery's voltage for an open switch or a blocking diode.


 


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