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Most Important Selected Qs for JEE AdvancedPhysicsWaves and Sound

A train moves towards a stationary observer with a speed of 34 ~ms ⁻¹ . The train sounds a whistle and its frequency registered by the observer is f₁ . If the train's speed is reduced to 17 ~ms ⁻¹ , the frequency registered is f₂ . If the speed of sound is 340 ~ms ⁻¹ , then the ratio f₁ f₂ is 10+x 18 . Calculate the value of x .

Correct answer

9

Step-by-step solution

f₁= ( 340 340-34 ) f= 10 9 f aligned & and f₂= ( 340 340-17 ) f= 20 19 f & and f₁ f₂ = 10 9 20 19 = 19 18 aligned

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