A common base transistor amplifier has an input resistance of 20 ohms and output resistance of 100 kilo-ohms.

A common base transistor amplifier has an input resistance of 20 ohms and output resistance of 100 kilo-ohms. The collector load is 1 kilo-ohm. If a signal of 500 mV is applied between emitter and base, find the voltage amplification. Assume a_ac to be nearly one

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Fig. 4.8 shows the conditions of the problem. Note that output resistance is very high as compared to input resistance. This is not surprising because input junction (base to emitter) of the transistor is forward biased while the output junction (base to collector) is reverse biased.


Comments: You may note that basic amplifying action is produced by transferring a current from a low-resistance to a high-resistance circuit. Consequently, the name transistor is given to the device by combining the two terms given in magenta letters below:

Transfer + Resistor -----> Transistor

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Wilfykil answered the question on August 14, 2019 at 12:52

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