An engine giving whistle is moving towards a stationary observer with $110\, m/s$ speed. What will be the ratio of the frequency of the whistle heard when the engine is approaching and receding from the observer ? (Speed of sound $= 330\, m/s$)
  • A$2 : 1$
  • B$1 : 2$
  • C$3 : 1$
  • D$5 : 2$
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
    A wave is represented by the equation$y = 7\sin \left( {7\pi t - 0.04\,x\pi + \frac{\pi }{3}} \right)$ $x$ is in metres and $ t$ is in seconds. The speed of the wave is
    View Solution
  • 2
    A composition string is made up by joining two strings of different masses per unit length $\rightarrow \mu$ and $4\mu$ . The composite string is under the same tension. A transverse wave pulse $: Y = (6 mm) \,\,sin\,\,(5t + 40x),$ where $‘t’$ is in seconds and $‘x’$ in meters, is sent along the lighter string towards the joint. The joint is at $x = 0$. The equation of the wave pulse reflected from the joint is
    View Solution
  • 3
    When two tuning forks (fork $1$ and fork $2$ ) are sounded together, $4$ beats per second are heard. Now some tape is attached on the prong of the fork $2$. When the tuning forks are sounded again, $6$ beats per second are heard. If the frequency of fork $1$ is $200 \,Hz$, then the original frequency of fork $2$ is ........... $Hz$
    View Solution
  • 4
    The end correction of a resonance column is $1\,cm.$  If the shortest length resonating with the tuning fork is $10\,cm,$  the next resonating length should be ..... $cm$
    View Solution
  • 5
    Two vehicles, each moving with speed $u$ on the same horizontal straight road, are approaching each other. Wind blows along the road with velocity $w$. One of these vehicles blows a whistle of frequency $f_1$. An observer in the other vehicle hears the frequency of the whistle to be $f _2$. The speed of sound in still air is $V$. The correct statement$(s)$ is (are) :

    $(A)$ If the wind blows from the observer to the source, $f_2 > f_1$.

    $(B)$ If the wind blows from the source to the observer, $f_2 > f_1$.

    $(C)$ If the wind blows from the observer to the source, $f _2 < f _1$.

    $(D)$ If the wind blows from the source to the observer, $f _2 < f _1$.

    View Solution
  • 6
    A tuning fork of frequency $340Hz$ is vibrated just above the tube of $120 cm$ height. Water is poured slowly in the tube. What is the minimum height of water necessary for the resonance .... $cm$ (speed of sound in the air $= 340 m/sec$)
    View Solution
  • 7
    The phase difference between two points separated by $1m$ in a wave of frequency $120 Hz$ is ${90^o}$. The wave velocity is .... $m/s$
    View Solution
  • 8
    $Assertion :$ The change in air pressure affects the speed of sound.
    $Reason :$ The speed of sound in gases is proportional to the square of pressure.
    View Solution
  • 9
    If two waves of same frequency and same amplitude respectively, on superimposition produced a resultant disturbance of the same amplitude, the waves differ in phase by
    View Solution
  • 10
    An engine is moving on a circular track with a constant speed. It is blowing a whistle of frequency $500 Hz$. The frequency received by an observer standing stationary at the centre of the track is
    View Solution