The model of a complete amplifier circuit is shown below.
a) If the amplifier's input resistance ($R_i$) is 1500 Ω, what is the range of values that the source resistance $R_s$ can have if we wish 90% or more of the current provided by the small signal current source ($i_s$) to be coupled into the amplifier?
b) If the amplifier's output resistance ($R_o$) is 200 Ω, what is the range of values that the load resistance $R_L$ can have if we wish 90% or more of the amplifier's dependent voltage source voltage to be delivered (i.e. dropped) to the load resistor?