Which one of the following is a semiconductor device that is used to increase the power of the incoming signals by preserving the shape of the original signal?

A transistor is a versatile semiconductor device that functions as both a switch and an amplifier. In its role as an amplifier, it increases the magnitude or power of an input signal by modulating power from an external supply. Linear amplifiers are specifically designed to preserve the shape and integrity of the original input signal while increasing its amplitude, a process referred to as 'gain'. This makes transistors fundamental in audio systems and radio receivers where weak signals must be strengthened without distortion. In contrast, a diode acts as a rectifier to allow current flow in only one direction, while registers and flip-flops are sequential logic elements used for data storage and memory rather than signal amplification [1]. Therefore, the transistor is the primary semiconductor device used to increase signal power while maintaining the original waveform.

Sources

1. [1] https://www.sciencedirect.com/topics/engineering/bistable-circuit