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The Voltage

How to measure a voltage

1) Multimeter and voltmeter

The voltage is measured using a voltmeter whose symbol is:

Standard symbol for voltmeter

The multimeter can measure a current but it can also measure a voltage.
In this case we use the voltmeter mode.
2) How to connect a multimeter in voltmeter mode ?

- Terminals: We use the COM terminal and a voltage terminal (V)
- The sense of connection: The COM terminal is closest to the negative terminal and the voltage terminal closest to the positive terminal of the electric generator.
- The insertion in the circuit: The multimeter is connected in parallel (The multimeter is connected to the component's terminals for which we want to know the voltage).

3) How to choose the range for multimeter in voltmeter mode ?

Definition: The chosen range corresponds to the highest voltage that the voltmeter can measure.

The range used should not be smaller than the measured voltage: the measure couldn't be made and the voltmeter may be damaged.
The range should not be too great otherwise the measurement looses its accuracy.

Method: We must first use the highest range for an approximation of the voltage and then choose the closest (but higher) to obtain a more accurate measurement.

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- Basic electrical components
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- 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
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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
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- What are alternating current and voltage ?
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- Oscilloscope
- Oscillogram
- Frequency
- Measuring RMS voltage with a voltmeter
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- Series circuit properties
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- Current law in series - circuits
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- Nodes and branches in parallel circuits
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Generating electricity
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- Alternating currents and voltages
- Generating electricity in power plants

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


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