The internal resistance of a voltage source with Cobra SMARTsenseoltage source

Principle

A commercially available dry battery or mono cell is well suited for investigating the internal resistance of voltage sources. Its internal resistance is high enough to be easily measurable and it is easy to replace if it is carelessly destroyed by prolonged overloading.

Tasks

1. Set up an electric circuit with different resistors and measure the current I and the terminal voltage Uc
2. Determine the internal resistance Ri of the voltage source by evaluating the measurement data.

Learning objectives

Students recognize that real voltage sources have an internal resistance and learn to determine this experimentally by measuring the current and clamping voltage.

Advantages

• No additional cable connections required between the components - clearer and faster assembly
• Contact reliability thanks to components that can be interlocked like a puzzle
• Hard gold-plated, corrosion-resistant contacts
• Double learning success: Electrical circuit diagram visible on the top and real components on the bottom