Why input resistance of a transistor is low?
While using a transistor, the emitter-base junction is always forward biased and the collector-base junction is always reverse-biased. Due to it, a small change in emitter current. This means that a small signal voltage variation at the input of the transistor produces a large emitter current variation. This showed that the input resistance of a transistor is low. Since the collector is reverse-biased, it collects all the charge carriers which diffuse into it, through the base. Due to it, a very large change in collector voltage shows only a small change in the collector current. This shows that the output resistance of the transistor is high.
How to Calculate Small-Signal Input Resistance given Emitter Current?
Small-Signal Input Resistance given Emitter Current calculator uses Small Signal = Signal Current*Emitter Resistance to calculate the Small Signal, The Small-signal input resistance given emitter current suggests that for a small signal, the transistor behaves as a voltage-controlled current source. The input port of the controlled current source is between base and emitter and the output port is in between collector and emitter. Small Signal is denoted by Vss symbol.
How to calculate Small-Signal Input Resistance given Emitter Current using this online calculator? To use this online calculator for Small-Signal Input Resistance given Emitter Current, enter Signal Current (isi) & Emitter Resistance (Re) and hit the calculate button. Here is how the Small-Signal Input Resistance given Emitter Current calculation can be explained with given input values -> 0.9275 = 0.00265*350.