A source producing sound of frequency $170 Hz$ is approaching a stationary observer with a velocity $17 \,ms^{-1}$. The apparent change in the wavelength of sound heard by the observer is (speed of sound in air $= 340 \,ms^{-1}$)  ..... $m$
Medium
Download our app for free and get startedPlay store
(a) $\lambda = \frac{v}{n} = \frac{{340}}{{170}} = 2m,\,\,\,n' = \frac{{340}}{{340 - 17}} \times 170 \Rightarrow n' = 178.9Hz$
Now $\lambda ' = \frac{v}{{n'}} = \frac{{340}}{{178.9}} = 1.9$
==> $\lambda - \lambda ' = 2 - 1.9 = 0.1$
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
    The wave equation is $y = 0.30\sin (314t - 1.57x)$ where $t, x$ and $y$ are in second, meter and centimeter respectively. The speed of the wave is ..... $m/s$
    View Solution
  • 2
    The length of an open organ pipe is twice the length of another closed organ pipe. The fundamental frequency of the open pipe is $100\ Hz$ . The frequency of the third harmonic of the closed pipe is ..... $Hz$
    View Solution
  • 3
    A driver in a car, approaching a vertical wall notices that the frequency of his car horn, has changed from $440\, Hz$ to $480 \,Hz ,$ when it gets reflected from the wall. If the speed of sound in air is $345 \,m / s ,$ then the speed of the car is $.......km/hr$
    View Solution
  • 4
    The apparent frequency of a sound wave as heard by an observer is $10\%$ more than the actual frequency. If the velocity of sound in air is $330\,m/sec$ , then

    $(i)$ The source may be moving towards the observer with a velocity of $30\,ms^{-1}$

    $(ii)$ The source may be moving towards the observer with a velocity of $33\,ms^{-1}$

    $(iii)$ The observer may be moving towards the source with a velocity of $30\,ms^{-1}$

    $(iv)$ The observer may be moving towards the source with a velocity of $33\,ms^{-1}$

    View Solution
  • 5
    A steel rod of length $100\, cm$ is clamped at the middle. The frequency of the fundamental mode for the longitudinal vibrations of the rod is ..... $kHz$ (Speed of sound in steel $= 5\, km\, s^{-1}$)
    View Solution
  • 6
    In a simple harmonic wave, minimum distance between particles in same phase always having same speed, is ..........
    View Solution
  • 7
    A motor cycle starts from rest and accelerates along a straight path at $2 \;m / s ^{2}$. At the starting point of the motor cycle there is a stationary electric siren. How far has the motor cycle gone when the driver hears the frequency of the siren at $94 \%$ of its value when the motor cycle was at rest?

    (Speed of sound $=330 ms ^{-1}$)

    View Solution
  • 8
    The string of a violin has a frequency of $440 \,cps$. If the violin string is shortened by one fifth, its frequency will be changed to ........... $cps$
    View Solution
  • 9
    The nature of sound waves in gases is
    View Solution
  • 10
    $Assertion :$ Speed of wave $=\frac{wavelength}{time period}$
    $Reason :$ Wavelength is the distance between two nearest particles in phase.
    View Solution