The power brick for the author’s laptop computer (Fig. 22.30) has the following power specifications: AC 100 V/1.6 A; DC 16.5 V/3.6 A. Here, the numbers following “AC” describe the input to the power brick (from the AC power line) and the numbers following “DC” describe the DC output to the laptop. What do these numbers tell you about the efficiency with which the power brick converts AC to DC? That is, what is P_DC /P_AC , the ratio of the DC power output to the AC power input? If some power is “lost,” where do you think it goes?