What is the most convenient tool for testing a transistor?

A multimeter is the most convenient tool for testing a transistor because it can measure both current and voltage, which are essential for evaluating a transistor’s operation. Using a multimeter, you can check the transistor's gain (hFE), determine whether it is functioning as expected, and identify faulty transistors effectively. It is also capable of measuring resistance, allowing you to check the transistor's junctions in both forward and reverse biases to see if they are open or shorted.

On the other hand, while an oscilloscope provides valuable insight into signal waveforms and performance under dynamic conditions, it is more complex and not always necessary for simple transistor testing. Logic analyzers are designed for analyzing digital signals and are not suitable for testing the analog properties of transistors. Similarly, a signal generator is used primarily to create test signals rather than to analyze a transistor's operation directly. Therefore, the multimeter stands out as the most practical and user-friendly tool for basic transistor testing.