How to check diodes and transistors using a multimeter

 An important parameter in a transistor is hFE, which represents the current gain of a bipolar junction transistor. Bipolar junction transistors have a collector, base and emitter. hFE is also known as the β of the transistor. hFE stands for Hybrid parameter Forward current gain, common Emitter. It is measured by dividing the collector current by the base current in a common emitter configuration and measures the amplification of the transistor.



When a diode is forward biased, meaning that the positive pole of the battery is connected to the anode of the diode, there is a small drop in the potential across the diode, typically 0.7 V in a silicon diode. In rectifier diodes, cathode is marked as a ring or stripe on the body near the cathode pin or lead. When the diode is reverse biased, no current flows across it, as when the anode is connected to the negative terminal of the battery.


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