A tuning fork of known frequency makes beats per second with the vibrating string of a piano. The beat frequency decreases to beats per second when the tension in the piano string is slightly increased. The frequency of the piano string before increasing the tension was:
- A
- B
- C
- D
Solution & Step-by-step Explanation
Initial frequency of piano string is either or .When tension increases, increases.If was , increasing it makes it further from , so beats would increase ().If was , increasing it brings it closer to , so beats would decrease ().Since beats decreased to , the original frequency must have been , which is .