When we change a feeble sound to a loud sound, we increase its:

A musical instrument is producing a continuous note. This note cannot be heard by a person having a normal hearing range. This note must then be passing through:

Which of the following sound frequencies can be heard by a woman having a normal hearing range?

A) 25000 Hz

B) 15kHz

C) 40000 Hz

D) 25Hz

Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the strings suitably. By doing so he is adjusting:

A key of mechanical piano is first struck gently and then struck again but much harder this time. In the second case: