Question

Standing waves are produced in a 10 m long stretched string. If the string vibrates in 5 segments and the wave velocity is 20 m/s, the frequency is

• A. 2 Hz
• B. 4 Hz
• C. 5 Hz
• D. 10 Hz

Answer 1

Answer: (C)

5 Hz

Answer 2

String vibrates in five segment so $\frac{5}{2}\lambda = l$ ⇒ $\lambda = \frac{2l}{5}$

Hence $n = \frac{v}{\lambda} = 5 \times \frac{v}{2l} = 5 \times \frac{20}{2 \times 10} = 5Hz$