A) 3
B) 6
C) 9
D) zero
Correct Answer: B
Solution :
Observed frequency of first train \[{{n}_{1}}=\frac{v}{v-{{v}_{s}}}\times n\] \[=\frac{320}{320-4}\times 240\] \[=\frac{320}{316}\times 240\] \[=243\,Hz.\] Observed frequency of second train \[{{n}_{2}}=\frac{v}{v+{{v}_{s}}}n\] \[=\frac{320}{320+4}\times 240\] \[=237\,Hz.\] \[\therefore \] Number of beats\[=243-237=6\]You need to login to perform this action.
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