What type of signal has finite power but may have finite or infinite energy?

The correct answer is a power signal. A power signal is characterized by having a finite average power over time, which means it can continuously exist and transmit energy without a defined end, such as a periodic waveform (e.g., a sine wave) that repeats over time. Because power signals can continue indefinitely, they are considered to have finite power.

On the other hand, energy signals are defined as having finite energy, meaning their total energy is limited to a specific value when observed over a finite time interval. They typically decay over time, leading them to not persist indefinitely.

In contrast, the term "bandpass signal" refers to a signal that has been filtered to allow frequencies within a certain range to pass through while attenuating frequencies outside that range. While bandpass signals can be power signals or energy signals depending on their characteristics, the defining attribute concerning power and energy pertains specifically to the types of signals mentioned earlier.

Thus, the defining characteristic of power signals is what makes this answer valid within the context of the question regarding power and energy.