Question

Which of the following sounds are not audible?

• A. a tuning fork vibrating 400 times in 2 sec.
• B. a tuning fork vibrating 3600 times in 60 s.
• C. tuning fork vibrating 1 time in 1 sec
• D. tuning fork vibrating 900 times in 2 sec

Answer 1

The correct option is C tuning fork vibrating 1 time in 1 sec

The range of audible frequency is 20 Hz - 20,000 Hz.
In the first case frequency of the tuning fork will be 200 Hz.
In second case it will be 60 Hz.
In third case frequency will be 1 Hz ,which is out of the audible frequency range.