Home
Class 11
PHYSICS
A source is moving towards an observer w...

A source is moving towards an observer with a speed of 20 m / s and having frequency of 240 Hz . The observer is now moving towards the source with a speed of 20 m / s . Apparent frequency heard by observer, if velocity of sound is 340 m / s , is

A

240 Hz

B

270 Hz

C

280 Hz

D

360 Hz

Text Solution

Verified by Experts

The correct Answer is:
B
`f.=f((v+v_(o))/(v-v_(s)))`
`implies f.=240((340+20)/(340-20))=240xx(360)/(320)`
`implies f.=270Hz`.
Promotional Banner

Topper's Solved these Questions

  • WAVES AND SOUND

    ERRORLESS|Exercise NCERT BASED QUESTIONS (MUSICAL SOUND) |17 Videos

  • WAVES AND SOUND

    ERRORLESS|Exercise PAST YEARS QUESTIONS |45 Videos

  • WAVES AND SOUND

    ERRORLESS|Exercise NCERT BASED QUESTIONS (ORGAN PIPE (VIBRATION OF AIR COLUMN)) |16 Videos

  • UNITS, DIMENSIONS AND MEASUREMENT

    ERRORLESS|Exercise ASSERTION & REASON |17 Videos

  • WORK, ENERGY POWER AND COLLISION

    ERRORLESS|Exercise ASSERTION & REASON |22 Videos

Similar Questions

Explore conceptually related problems

A source of sound of frequency 500 Hz is moving towards an observer with velocity 30 m/s . The speed of sound is 330 m/s . the frequency heard by the observer will be

If a source emitting waves of frequency f moves towards an observer with a velocity (v)/(4) and the observer moves away from the source with a velocity (v)/(6) , the apparent frequency as heard by the observer will be (v=velocity of sound)

a bus is moving towards and stationary observer with speed 20 m/s blows a horn of frequency 200 Hz. the frequency of sound heard by the observer is approximately ( take speed of sound 320 m/s)

A source of sound, producing a sinusoidal wave, is moving uniformly towards an observer at a velocity of 20 m/s. The observer is moving away from the source at a constant velocity of 10 m / s. Frequency of the source is 200 Hz and speed of sound in air is of 340 m/s. (a) How many times, in an interval of 10 second, the eardrums of the observer will sense maximum change in pressure? (b) What will be apparent wavelength of sound for the observer?

A source of sound is approaching an observer with speed of 30 m/s and the observer is approaching the source with a speed 60 m/s. Then the fractional change in the frequency of sound in air (330 m/s) is

A source of sound emitting a note of frequency 200 Hz moves towards an observer with a velocity v equal to the velocity of sound. If the observer also moves away from the source with the same velocity v, the apparent frequency heard by the observer is

The frequency of a whistle of an engine is 600 cycles / sec is moving with the speed of 30 m / sec towards an observer. The apparent frequency will be (velocity of sound = 330 m / s )

ERRORLESS-WAVES AND SOUND -NCERT BASED QUESTIONS (DOPPLER.S EFFECT)
  1. A source producing sound of frequency 170 Hz is approaching a stationa...

    Text Solution

    |

  2. A train approaches stationary observer, the velocity of train being 1/...

    Text Solution

    |

  3. A whistle of frequency 500 Hz tied to the end of a string of length 1....

    Text Solution

    |

  4. A car sounding a horn of frequency 1000 Hz passes an observer. The rat...

    Text Solution

    |

  5. A small source of sound moves on a circle as shown in figure and an ob...

    Text Solution

    |

  6. A man is watching two trains, one leaving and the other coming in with...

    Text Solution

    |

  7. A train whistling at constant frequency is moving towards a station at...

    Text Solution

    |

  8. A car is moving with 90 km h^(-1) blows a horn of 150 Hz, towards a cl...

    Text Solution

    |

  9. A source and an observer move away from each other with a velocity of ...

    Text Solution

    |

  10. A source is moving towards an observer with a speed of 20 m / s and ha...

    Text Solution

    |

  11. A police car moving at 22 m/s, chases a motorcylist. The police man so...

    Text Solution

    |

  12. A whistle emitting a loud sound of frequency 540 Hz is whirled in a ho...

    Text Solution

    |

  13. A source of sound of frequency 500 Hz is moving towards an observer wi...

    Text Solution

    |

  14. A band playing music at a frequency f(0) is moving towareds a wall at ...

    Text Solution

    |

  15. Two tuning forks P and Q are vibrated together . The number of beats p...

    Text Solution

    |

  16. A racing car moving towards a cliff, sounds its horn. The driver obser...

    Text Solution

    |

  17. A man standing in front of a mountain beats a drum at regular interval...

    Text Solution

    |

  18. An engine moving away from a vertical cliff blows a born at a frequenc...

    Text Solution

    |

  19. 25 tuning forks are arranged in series in the order of decreasing freq...

    Text Solution

    |

  20. A hearing test is conducted on an aged person. It is found that her th...

    Text Solution

    |