2. Solved Papers
  3. BCECE Engineering

BCECE Engineering BCECE Engineering Solved Paper-2005

  • question_answer
    A string of length 2 m is fixed at both ends. If this string vibrates in its fourth normal mode with a frequency of 500 Hz, then the waves would travel on it with a velocity of:

    A)  125 m/s                              

    B)         250 m/s

    C)         500 m/s                              

    D)         1000 m/s

    Correct Answer: C

    Solution :

    A normal mode of an oscillating system is a motion in which all particles of the system move sinusoidally with the same frequency. In general, \[pth\]mode of a string fixed at ends has frequency. \[n=\frac{pv}{2l}\]           \[p=1,2,3..\] where\[v\] is velocity of wave and I is length of string. In fourth normal mode, \[p=4\] \[\therefore \,\]              \[n=\frac{4v}{2l}\] Given,  \[n=500\,Hz,l=2\,m\] Hence,  \[500\,=\frac{4v}{2\times 2}\] or   \[v=\frac{500\times 4}{4}=500\,m/s\]


You need to login to perform this action.
You will be redirected in 3 sec spinner