Amp Up Your Knowledge: 2025 Electronics Engineering Board Exam Bash!

The selected answer, Serial-In Serial-Out (SISO), is correct because this type of register is designed specifically to accept a binary number one bit at a time (serially) and then output that same number one bit at a time, also serially. The fundamental operation of a SISO register involves shifting the bits through a series of flip-flops, where each clock pulse shifts the bits to the next stage, allowing the complete binary number to be shifted out sequentially.

This shifting operation makes SISO registers particularly useful in applications where data needs to be transmitted over a single line or where the available bandwidth for data transfer is limited. The serial input allows for efficient use of connection resources by reducing the number of lines needed compared to parallel communication methods.

Other types of registers, while useful in their own contexts, perform different functions. For example, a Parallel-In Serial-Out (PISO) register allows multiple bits to be loaded in simultaneously (parallel) but then outputs them serially, which does not match the requirement of shifting one bit at a time from a single stored binary number. Similarly, a Serial-In Parallel-Out (SIPO) register takes in bits serially but can output all the stored bits simultaneously in parallel, which means it does