A source of unknown frequency gives $4\,\, beats/s$ when sounded with a source of known frequency $250\,\, Hz.$ The second harmonic of the source of unknown frequency gives five beats per second, when sounded with a source of frequency $513\,\, Hz.$ The unknown frequency is .... $Hz$
A$246$
B$240$
C$260$
D$254$
AIPMT 2013, Medium
Download our app for free and get started
D$254$
d Let $v$ be frequency of the unknown source.
As it gives 4 beats per second when sounded with a source of frequency $250 \mathrm{Hz}$
$\therefore \quad v=250 \pm 4=246 \mathrm{Hz}$ or $254 . \mathrm{Hz}$
Second harmonic of this unknown source$=492 \mathrm{Hz}$ or $508 \mathrm{Hz}$ which gives $5$ beats per second, when sounded with a source of frequency $513 \mathrm{Hz}$ Therefore unknown frequency, $v=254 \mathrm{Hz}$.
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.*
A narrow tube is bent in the form of a circle of radius $R,$ as shown in the figure. Two small holes $S$ and $D$ are made in the tube at the positions right angle to each other. A source placed at $S$ generated a wave of intensity $I_0$ which is equally divided into two parts : One part travels along the longer path, while the other travels along the shorter path. Both the part waves meet at the point $D$ where a detector is placed The maximum value of $\lambda$ to produce a minima at $D$ is given by
If speed of sound in air in $330 \,m / s$ then, find the number of tones present in an open organ pipe of length $1\, m$ whose frequency if $\leq 1000$.
A person driving car at a constant speed of $15\,m / s$ is approaching a vertical wall. The person notices a change of $40\,Hz$ in the frequency of his car's horn upon reflection from the wall. The frequency of horn is ............ $Hz$. (Given : Speed of sound : $330\,m / s$ )
In a large room, a person receives direct sound waves from a source $120$ metres away from him. He also receives waves from the same source which reach him, being reflected from the $25$ metre high ceiling at a point halfway between them. The two waves interfere constructively for wavelength of
The fundamental frequency of a sonometer wire increases by $6$ $Hz$ if its tension is increased by $44\%$ keeping the length constant. The change in the fundamental frequency of the sonometer wire in $Hz$ when the length of the wire is increased by $20\%$, keeping the original tension in the wire will be :-
Three musicians experiment with the Doppler effect. Musician $A$ rides in a car at a speed $u$ directly away from musician $B$ who is stationary. Musician $C$ rides in a car directly toward $B$ and travels at the same speed as $A$ . Musician $A$ plays a note at frequency $f_A$ on his trumpet $B$ hears the note, adjusts his trumpet, and plays the same note he heard. Choose the incorrect statement
In a Resonance -Coulmn lab experiment to measure the velocity of sound, the first resonance is obtained at a length $l_1$ and the second resonance at a length $l_2$. Then-
A string is clamed at both the ends and it is vibrating in its $4^{th}$ harmonic. The equation of the stationary wave is $Y =0.3\,sin\,(0.157\,x) \,cos\,(200\pi t)$. The length of the string is ..... $m$ (all quantities are in $SI$ units)
In a resonance tube the first resonance with a tuning fork occurs at $16 cm$ and second at $49 cm.$ If the velocity of sound is $330 m/s,$ the frequency of tuning fork is