A) 30
B) 34
C) 12
D) 15
Correct Answer: A
Solution :
We know that Frequency (v) \[=\frac{velocity\text{ }\left( v \right)}{wavelength\text{ }\left( \lambda \right)}\] Given, \[v=360\,m/s,\,\lambda =2.4\,m\] \[\therefore \] \[v=\frac{360}{2.4}=150\,Hz\] Given, frequency of rotation per minute = 300 \[\therefore \] Time taken for one rotation \[=\frac{1}{300}\min \] \[=\frac{60}{300}s\] Since, frequency is 150 Hz, time taken to travel from one hole to another \[=\frac{1}{150}s\]. \[\therefore \] \[\frac{1}{5n}=\frac{1}{150}\] \[\Rightarrow \] \[n=30\]You need to login to perform this action.
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