Final answer:
The statement that a narrow rBW will pick up less noise, increasing SNR, is true. Additionally, the amplitude of one wave is affected by another only when they are precisely aligned, which is also true.
Step-by-step explanation:
The statement 'A narrow rBW will pick up less noise than a larger rBW. decreasing rBW increases SNR by decreasing noise' is true. Reducing the resolution bandwidth (rBW) of a measurement system does indeed reduce the noise levels because it narrows the range of frequencies that are integrated over to compute the power at a given point. Since random noise typically spreads across all frequencies, by narrowing the bandwidth, the system picks up less noise thereby increasing the signal-to-noise ratio (SNR). When two waves are misaligned, their amplitudes do not affect each other; however, when they align precisely, which is known as 'constructive interference,' the amplitude of one wave can indeed affect and enhance the amplitude of the other. This can also work in reverse, where they can cancel each other out in 'destructive interference' if their amplitudes are opposite. So the answer to the second part of the question would be 'true.' The amplitude of one wave being affected by another is contingent on their alignment.