Final answer:
Waves affect each other's amplitude due to interference when aligned, dropping a magnet through a copper tube induces an electric current, and waves of different frequencies can superimpose.
Step-by-step explanation:
The statement 'The amplitude of one wave is affected by the amplitude of another wave only when they are precisely aligned' is true. This principle relates to the concept of wave interference, specifically constructive and destructive interference. When two waves are perfectly in sync (in phase), their amplitudes add up, resulting in constructive interference. Conversely, when the waves are out of sync (out of phase), they can cancel each other out, which is known as destructive interference.
Dropping a bar magnet through a copper tube does indeed induce an electric current in the tube according to Faraday's Law of Electromagnetic Induction, making this statement true. When a magnetic field changes in a conductor, it produces an electric current.
It is also true that waves can superimpose if their frequencies are different. This can result in a complex pattern of interference, but the waves do not need to have the same frequency to interact.