Question

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

• A. $5Hz$
• B. $2Hz$
• C. $10Hz$
• D. $12Hz$

Answer 1

The correct option is A $5Hz$

There are $5$ loops in $10$ metre.
Length of one loop $=2m$
Length of two loops $=2\times 2=4m$
Now, $\lambda =4m;v=20m/sec$
From formula, $v=v\lambda .\Rightarrow 20=v\times 4\Rightarrow v=5Hz$