1.50 A 10-mV signal source having an internal resistance of 5 kΩ is connected to an amplifier for which the input resistance is 1 kΩ, the open-circuit voltage gain is 100 V/V, and the output resistance is 200 Ω. The amplifier is connected in turn to a 100-Ω load.
(a) What overall voltage gain results as measured from the source internal voltage to the load? Where did all the gain go? What would the gain be if the source was connected directly to the load? What is the ratio of these two gains? This ratio is a useful measure of the benefit the amplifier brings.
(b) Now instead, replace the source by its Norton equivalent and the amplifier with the equivalent current amplifier from Table 1.1. What is the current gain, io/is? Show that it is the same as would be computed using the voltage amplifier model.