Home
Class 11
PHYSICS
A whistle revolves is a circle with angu...

A whistle revolves is a circle with angular velocity w= 20 rad/s using a string of length 50 cm. If the actual frequency of sound from the whistle is 385 Hz. Then the minimum frequency heard by the observer far away from the centre is ( velocity of sound v=340 m/s)

A

385 Hz

B

374 Hz

C

394 Hz

D

333 Hz

Text Solution

Verified by Experts

The correct Answer is:
B
`f_(min)=f_(o)((v)/(v+omegaR))=385((340)/(340+20xx0.5))=374Hz`
Promotional Banner

Topper's Solved these Questions

  • WAVES AND OSCILLATIONS

    ALLEN|Exercise Part-1(Exercise-02)|19 Videos

  • WAVES AND OSCILLATIONS

    ALLEN|Exercise Part-1(Exercise-03)|31 Videos

  • WAVES AND OSCILLATIONS

    ALLEN|Exercise Part-3(Example)|32 Videos

  • SEMICONDUCTORS

    ALLEN|Exercise Part-3(Exercise-4)|51 Videos

Similar Questions

Explore conceptually related problems

A whistle revolves in a circle with an angular speed of 20 rad//sec using a string of length 50 cm . If the frequency of sound from the whistle is 385 Hz , then what is the minimum frequency heard by an observer which is far away from the centre in the same plane? v=340m//s

(i) What is beat phenomenon? (ii) A whistle revolves in a circle with angular velocity of omega=20rads^(-1) . If the frequency of sound is 385 Hz and speed is 340 ms^(-1) , then find the frequency heard by the observer when the whistle is at B.

An observer a sitting on a cart executing SHM between A and B listens to a whistle which rotates in a circle with constant speed 5 m/s as shown.The maximum speed of the car is same as that of whistle . If frequency of the whistle is 640 Hz,then maximum possible frequency observed by observer is [Speed of sound in air= 320 m/s]

A siren emitting sound of frequency 800 Hz is going away from a static listener with a speed of 30 m/s. Frequency of the sound to be heard by the listener is ( Take velocity of sound as 300 m/s )

A disc of radius R is rotating uniformly with angular frequency . A source of sound is fixed to the rim of the disc. The ratio of maximum to minimum frequency heard by a stationary observer, far away from the disc and in the plane of the disc is: (v = speed of sound)

A whistle of frequency 500 Hz is rotated in a circle of radius cne metre with an angular speed of 10 radian/sec. Calculate the lowest and the highest frequency heard by a listener at a long distance away at rest with respect to the centre of the circle ? (Velocity of sound = 340m/s)

A car moving at a speed of 72km/hr sounds its whistle which has a frequency of 550Hz, Find the frequencies heard by a stationary observer as the car approaches and then recedes from the observer, velocity of sound =340m/s.

At t=0 , observer and source are at same place. Now the source is projected with velocity 60 sqrt2 m/s at 45 ^(@) . Natural frequency of source is 1000 Hz.find the frequency heard by the observer at t=2s. Take speed of sound = 340 m/s

A train blowing its whistle moves with a constant velocity v away from an observer on the ground. The ratio of the natural frequency of the whistle to that measured by the observer is found to be 1.2 . If the train is not rest and the observer moves away from it at the same velocity, this ratio would be given by

Two trains A and B approach a station from opposite sides, sounding their whistles. A stationary observer on the platform hears no beats. If the velocities of A and B are 15 m/s and 30 m/s respectively and the real frequency of the whistle of B is 600 Hz, find the real frequency of the whistle of A. (Velocity of sound = 330 m/s)

ALLEN-WAVES AND OSCILLATIONS-Part-1(Exercise-01)
  1. A cylindrical tube, open at both ends, has a fundamental frequency f i...

    Text Solution

    |

  2. An organ pipe P(1) closed at one end vibrating in its first harmonic a...

    Text Solution

    |

  3. An open pie is suddenly closed at one end with the result that the fre...

    Text Solution

    |

  4. The maximum length of a closed pipe that would produce a just audible ...

    Text Solution

    |

  5. A cylindrical tube (L = 129 cm) is in resonance with in tuning fork of...

    Text Solution

    |

  6. A closed organ pipe of radius r(1) and an open organ pipe of radius r(...

    Text Solution

    |

  7. Plane sound waves of wavelength 0.12 m are incident on two narrow slit...

    Text Solution

    |

  8. Two vibrating tunign forks produce progessive waves given by y(1)=4 ...

    Text Solution

    |

  9. Frequency of tuning fork A is 256 Hz. It produces 4 beats/second with ...

    Text Solution

    |

  10. Length of a sonometer wire is either 95 cm or 100 cm. In both the case...

    Text Solution

    |

  11. Two open pipes of length 25 cm and 25.5 cm produced 0.1 beat/second. T...

    Text Solution

    |

  12. 16 tuning forks are arranged in increasing order of frequency. Any two...

    Text Solution

    |

  13. Two tuning forks having frequency 256 Hz (A) and 262 Hz (B) tuning for...

    Text Solution

    |

  14. Two open pipes of length L are vibrated simultaneously. If length of o...

    Text Solution

    |

  15. (a) The power of sound from the speaker of a radio is 20 mW. By turnin...

    Text Solution

    |

  16. A sound absorber attenuates the sound level by 20 dB. The intensity de...

    Text Solution

    |

  17. A whistle giving out 450 H(Z) approaches a stationary observer at a sp...

    Text Solution

    |

  18. A person feels 2.5% difference of frequency of a motor-car horn. If th...

    Text Solution

    |

  19. Two trains A and B are moving in the same direction with velocities 30...

    Text Solution

    |

  20. A whistle revolves is a circle with angular velocity w= 20 rad/s using...

    Text Solution

    |