Why do Junction Transistors Amplify Current and not Voltage

Sir! I want to repeat this everyday: You are the best Electronics teacher in the whole world. Thank You very much!

Thanks for this latest refresher! You are a teacher of great talent 👍

Very, very helpful! I'm a vacuum tube guy trying to understand transistors, be them a BJT, FET, JFET, MOSFET... and the others. I've never heard BJTs described this way before. It's a lot of food for thought. Thank you!

I've done a lot of work in electrical circuits, but thanks to you, today I found out (basically) how an air-conditioner works! Very simply explained. Thanks!

My teacher told me that if I can imagine the BJT is a current controlled current source and MOSFET is a Voltage controlled resistor.

Another terrific explanation, Bob! Yet, if I may offer a different point of view, the way I always understood it, is that the base-emitter (input) current directly controls the collector-emitter (output) current. Thanks to Ohm's law, increasing base voltage causes a rise in base current, which in turn, raises collector current far higher. Finally, thanks again to Ohm's law, this rise in collector current causes a substantial drop in collector voltage. And, conversely, dropping base voltage would have the opposite effect on collector voltage! (P.S. - I should point out that this explanation applies specifically to common- emitter circuits!)

Thanks, really informative, clear and educative video.

A very informative video - Thanks Sir

Thank u sir for great explaination keep up the good job and godbless

Great video. Thanks

In the world we should value and look for linear relationship. What i learned from transistor

Short answer: Because that's how they work. There is always a relationship between voltage and current, and the operation of a BJT is best characterized by the current relationship.

How does it actually amplify the current? Maybe you can use the hybrid pi model to explain ?