Question

A key of a mechanical piano is first struck gently, and then harder. Which properties of the sound produced would remain unchanged?

• A. Amplitude
• B. Frequency
• C. Pitch
• D. Intensity

Answer 1

Answer: (B), (C)

The correct options are
B Frequency
C Pitch

When the key of a mechanical piano is struck harder, we put more energy in the vibrating system due to which amplitude increases and thereby, a loud sound is produced. The intensity of the sound produced will also vary as the amplitude changes. On the other hand, the frequency of the sound would not change as it is the same key which is being struck. Also, since pitch is related to frequency, it will also remain unchanged.