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

Answer

Correct option: B.
$20$
b
(b) At fixed end node is formed and distance between two consecutive nodes $\Rightarrow$ $\frac{\lambda }{2} = 10$$cm$

$ \Rightarrow $$\lambda = 20$$cm$ 

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

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