A dc-to-dc converter (found in most laptop computers) has an input terminal pair that is connected to a battery and an output terminal pair that is connected to an unknown bounded load resistance. The converter is called a boost converter if the output voltage is larger than the input voltage. It is called buck converter under opposite conditions. Either way, one hopes for a high-efficiency conversion process in which the ratio of output to input power is not far below unity. An inefficient converter would quickly drain the battery. Show how you would connect two voltmeters and two ammeters to measure the converter efficiency with minimal error over several decades of load current.