A train, standing in a station-yard, blows a whistle of frequency $400\,Hz$ in still air. The wind starts blowing in the direction from the yard to the station with a speed of $10\,ms^{-1}$ then value of frequency and speed of sound for observer will be (the speed of sound in still is $340\, ms^{-1}$ )
  • A$400\,Hz,\,\,340\,m/sec$
  • B$>\,400\,Hz,\,\,340\,m/sec$
  • C$400\,Hz,\,\,350\,m/sec$
  • D$<\,400\,Hz,\,\,330\,m/sec$
Medium
art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    Two tuning forks, $A$ and $B$, give $4$ beats per second when sounded together. The frequency of $A$ is $320 Hz.$ When some wax is added to $B$ and it is sounded with $A, 4$ beats per second are again heard. The frequency of $B$ is  .... $Hz$
    View Solution
  • 2
    A sound is produced by plucking a string in a musical instrument, then
    View Solution
  • 3
    A closed pipe of length $10 \,cm$ has its fundamental frequency half that of the second overtone of an open pipe. The length of the open pipe ......... $cm$
    View Solution
  • 4
    An observer is riding on a bicycle and moving towards a hill at $18\,km\,h ^{-1}$. He hears a sound from a source at some distance behind him directly as well as after its reflection from the hill. If the original frequency of the sound as emitted by source is $640\,\,Hz$ and velocity of the sound in air is $320\,m / s$, the beat frequency between the two sounds heard by observer will be $...Hz$.
    View Solution
  • 5
    A wave travelling along the $x-$axis is described by the equation $y\left( {x,t} \right) = 0.005cos\left( {\alpha x - \beta t} \right)$ If the wavelength and the time period of the wave are $0.08\ m$ and $2.0\ s$, respectively, then $\alpha$ and $\beta$ in appropriate units are
    View Solution
  • 6
    Sound velocity is maximum in
    View Solution
  • 7
    If the phase difference between the two wave is 2$\pi $ during superposition, then the resultant amplitude is
    View Solution
  • 8
    A set of $20$ tuning forks is arranged in a series of increasing frequencies. If each fork gives $4$ beats with respect to the preceding fork and the frequency of the last fork is twice the frequency of the first, then the frequency of last fork is $\dots \; Hz$.
    View Solution
  • 9
    A person standing at a distance of $6\,\, m$ from a source of sound receives sound wave in two ways, one directly from the source and other after reflection from a rigid boundary as shown in the figure. The maximum wavelength for which, the person will receive maximum sound intensity, is  .... $m$
    View Solution
  • 10
    Two cars are moving on two perpendicular roads towards a crossing with uniform speeds of $72\; km/hr$ and $36\; km/hr$. If first car blows horn of frequency $280\; Hz,$ then the frequency of horn heard by the driver of second car when line joining the cars make $45^o$ angle with the roads; will be .... $Hz$
    View Solution