JEE AdvancedPhysicsWavesNumerical+4 / −1
A source (S) of sound has frequency . When the observer (O) and the source move towards each other at a speed with respect to the ground (as shown in Case 1 in the figure), the observer measures the frequency of the sound to be . However, when the observer and the source move away from each other at the same speed with respect to the ground (as shown in Case 2 in the figure), the observer measures the frequency of sound to be . The value of is . 

Numerical answer
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