Trans-istor. Trans-Resistor. Geddit? Current controlled voltage source. A typical BJT (Bipolar Junction Transistor) -- has about 4MOHM of DC resistance between the emitter and the collector. By applying (n) current at the base junction of the BJT, this in turn changes the resistance of the emitter to collector junctions. So it could be perceived as an current controlled variable resistor. So we take (n) small amount of current at the base to control a much larger amount of current at the collector OR the emitter. If an voltage is applied to the collector, the emitter voltage tends to follow the base voltage less 0.6V drop. This is called an emitter follower...
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