An observer while going on scooter hears sound of two sirens of same frequencies from two opposite directions. If he travels along the direction of one of the siren, then he
Easy
Download our app for free and get started
Let the two waves produced due to the two sirens have frequency and velocity as $v_1, v_1$ and $v_2, v_2$
Since, both are sound waves, we have $v_1=v_2=v$
For one wave the traveler is moving towards the source,
$\therefore v^{\prime}=v\left(\frac{v-v_0}{v}\right)$
For the other the traveler is moving away from the source
$\therefore v^{\prime}=v\left(\frac{v+v_0}{v}\right)$
Seeing this, we can conclude that the waves are in phase with each other and are fluctuating repeatedly.
Since, they are sound waves they are periodic in nature. Hence, we got two waves that are periodic and are repeatedly fluctuating. This is the condition of beats. So, beats will be produced and the traveler will listen to beats.
Option $(B)$ is the correct answer.
Download our appand 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
- 1A sound source of frequency $170 Hz$ is placed near a wall. A man walking from a source towards the wall finds that there is a periodic rise and fall of sound intensity. If the speed of sound in air is $340\, m/s$ the distance (in metres) separating the two adjacent positions of minimum intensity isView Solution
- 2An organ pipe $P_1$ closed at one end vibrating in its first overtone. Another pipe $P_2$ open at both ends is vibrating in its third overtone. They are in a resonance with a given tuning fork. The ratio of the length of $P_1$ to that of $P_2$ isView Solution
- 3A string is fixed at both ends vibrates in a resonant mode with a separation $2.0 \,\,cm$ between the consecutive nodes. For the next higher resonant frequency, this separation is reduced to $1.6\,\, cm$. The length of the string is .... $cm$View Solution
- 4A transverse wave is described by the equation $Y = {Y_0}\sin 2\pi \left( {ft - \frac{x}{\lambda }} \right)$. The maximum particle velocity is four times the wave velocity ifView Solution
- 5At $23^{\circ} C$, a pipe open at both ends resonates at a frequency of $450 \,Hz$. At what frequency does the same pipe resonate on a hot day when the speed of sound is $4 \%$ higher than it would be at $23^{\circ} C$ ?View Solution
- 6A source of sound $S$ of frequency $500 Hz$ situated between a stationary observer $O$ and a wall $W$, moves towards the wall with a speed of $2 m/s$. If the velocity of sound is $332 m/s$, then the number of beats per second heard by the observer is (approximately)View Solution
- 7View SolutionIf the amplitude of sound is doubled and the frequency reduced to one-fourth, the intensity of sound at the same point will be
- 8View SolutionWhich one of the following statements is true
- 9A tuning fork of frequency $340\, Hz$ 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 air $= 340\, m/s$)View Solution
- 10View SolutionIn stationary wave