Final answer:
The statement about wave amplitude affected only during precise alignment is false, whereas it is true that wave amplitudes add when propagating in the same line and waves of different frequencies can superimpose. Efficiency of machines is less than 100% due to energy losses, and wave energy is proportional to amplitude.
Step-by-step explanation:
The statement that the amplitude of a wave is affected by the amplitude of another wave only when they are precisely aligned is false. When waves meet, they superimpose, and the resultant amplitude can vary depending on their alignment, a concept known as interference. Also, the statement that amplitudes of waves add up only if they are propagating in the same line is true, as this describes constructive interference, where two waves in phase increase the wave's amplitude. Additionally, it's also true that waves can superimpose if their frequencies are different, which can lead to complex interference patterns.
Regarding the efficiency of a pulley or any simple machine, it is true that efficiency is always less than 100 percent due to energy losses like friction, which converts some work into heat. Hence, the efficiency can never be 100% as some energy is always lost. Lastly, the energy of a wave indeed increases with an increase in the amplitude of the wave, and the energy is spread over a larger area with increasing distance from the source, reducing amplitude.