Aim of this chapter is reinforcing the content of Chap. 3 by means of exercises focused on the identification of basic patterns, the DC analysis, and the AC small-signal analysis. A first set of exercises addresses the spotting of basic patterns without any following calculation. A second set of exercises exploits the pattern identification to develop the DC analysis, followed by the AC small-signal analysis. From the DC analysis you calculate the bias point of the transistors, verify if they are correctly biased, and calculate the numerical values of their small-signal parameters. In the AC analysis you use, the AC mathematical properties of the basic patterns to calculate the mathematical expressions of the small-signal properties of the circuit under investigation. All the exercises of these first two sets are fully solved and discussed. Eventually, a third set of exercises, still focused on the DC and AC analysis, closes the chapter but without offering a full discussion. The final equations and numerical results only are provided, by leaving to the reader honor and duty of their mathematical demonstration.