What type of resistance does the collector-base junction of a properly biased transistor have?

The collector-base junction of a properly biased transistor exhibits high resistance when the transistor is in the active or cutoff region. In these modes, the junction is reverse-biased, which means that voltage applied to the collector relative to the base creates a barrier that prevents current from flowing through the collector-base path. This high resistance is crucial as it allows the transistor to function effectively as an amplifier or switch without unwanted current leakage.

When a transistor operates in active mode, the primary current flow occurs from collector to emitter, with the collector-base junction serving as a control element where minimal current should flow. Consequently, a high resistance at the collector-base junction ensures that the transistor can efficiently control the flow of current based on the base-emitter junction's input voltage without undesired conduction that could lead to instability or malfunction.

This high resistance characteristic is essential for maintaining the transistor's functionality in amplification and switching applications, ensuring that it can operate under varying conditions while remaining responsive to control voltages.