Question

A wave of frequency 100 Hz is sent along a string towards a fixed end. When this wave travels back after reflection, a node is formed at a distance of 10 cm from the fixed end of the string. The speed of incident (and reflected) wave are

• A. 40 m/s
• B. 20 m/s
• C. 10 m/s
• D. 5 m/s

Answer 1

Answer: (B)

20 m/s

Answer 2

At fixed end node is formed and distance between two consecutive nodes $\frac{\lambda}{2} = 10cm \Rightarrow \lambda = 20cm$

$\Rightarrow$ $v = n\lambda = 20$ m/sec