Formula: Practical (Real) Voltage Source Terminal Voltage    Source voltage    Internal resistance    Load resistance

Formula: Practical (Real) Voltage Source
Circuit with a Practical Voltage Source

Terminal Voltage

Electrical voltage of an ideal voltage source MINUS the voltage across the internal resistance \(R_{\text i}\).

It can be seen from the formula that the terminal voltage depends on both the internal resistance of the voltage source and the load resistance.

Source voltage

Voltage of an ideal voltage source - by definition, it has infinite resistance.

Internal resistance

Resistance of a practical (real) voltage source.

Load resistance

Electrical resistance connected to the terminals (to which the terminal voltage is applied). The terminal voltage and source voltage are equal when the internal resistance is zero.

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