The note produced by a stretched string has a fundamental frequency of 400Hz. If the...
PHYSICS
JAMB 1994
The note produced by a stretched string has a fundamental frequency of 400Hz. If the length of the string is doubled while the tension in the string is increased by a factor of 4, the frequency is
- A. 200Hz
- B. 400Hz
- C. 800Hz
- D. 1600Hz
Correct Answer: B. 400Hz
Explanation
F = \(\frac {1}{2L}\) \(\sqrt\frac{T}{m}\)
T2 = 4T1 ; L2 = 2L1
\(\frac{2F_1L_1}{2F_2L_2}\) = \(\sqrt\frac{T_1}{T_2}\)
\(\frac{400\times L_1}{F \times L_1}\) = \(\sqrt\frac{T_1}{4T_1}\)
F = 400Hz
Post an Explanation Or Report an Error
If you see any wrong question or answer, please leave a comment below and we'll take a look. If you doubt why the selected answer is correct or need additional more details? Please drop a comment or Contact us directly. Your email address will not be published. Required fields are marked *