A) 12
B) 0
C) 3
D) 6
Correct Answer: D
Solution :
[d] The apparent frquency of sound of both the trains will be changed. The apparent frequency of sound of train coming in\[=240\times \frac{320}{320-4}\] \[=\frac{240\times 320}{316}=243\] For apparent frequency of train going away \[=240\times \frac{320}{320+4}=237\] When these sounds are heard simultaneously beat is listened. No. of beats per sec \[=243-237=6.\]You need to login to perform this action.
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