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KVPY2014PhysicsWaves and Sound

A whistle emitting a loud sound of frequency 540 ~Hz is whirled in a horizontal circle of radius 2 ~m and at a constant angular speed of 15 rad / s . The speed of sound is 330 ~m / s . The ratio of the highest to the lowest frequency heard by a listener standing at rest at a large distance from the center of the circle is :

Options

  1. A1.0
  2. B1.1
  3. C1.2
  4. D1.4

Correct answer

C. 1.2

Step-by-step solution

n^ =n [ v-0 v+v_ s ]n "=n [ v v+v_ s ] n^ n^ = v-v_ s v+v_ s n^ n^ = v+v_ s v-v_ s = 330+30 330-30 = 360 300 =1.2

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