A) 360 m/s
B) 340 m/s
C) 331 m/s
D) 306 m/s
Correct Answer: D
Solution :
Number of beats per second = difference of the frequencies of sound-source. \[\therefore \] Number of beats \[=\frac{v}{{{\lambda }_{1}}}-\frac{v}{{{\lambda }_{2}}}\] Given, \[{{\lambda }_{1}}=50\,cm=0.5\,m,\,{{\lambda }_{2}}=51\,cm\] \[=0.51\,\,m\] \[\therefore \] \[12=v\left( \frac{1}{0.5}-\frac{1}{0.51} \right)\] \[12=v\,\,(2-1.9608)\] \[\Rightarrow \] \[v=\frac{12}{0.0392}=306.12\,m/s\] = 306 m/s
You need to login to perform this action.
You will be redirected in
3 sec
