Two trains, one coming towards and another going away from an observer both at $4\; m/s$ produce whistle simultaneously of frequency $300 \;Hz$. Find the number of beats produced
A$5$
B$6$
C$7$
D$12$
Medium
Download our app for free and get started
C$7$
c (c) $\Delta n = \left[ {\frac{v}{{v - u}} - \frac{v}{{v + u}}} \right]\,n = \frac{{2uv}}{{{v^2} - {u^2}}}n$
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.*
Two vibrating tuning forks produce progressive waves given by $Y_1 = 4\, sin\, 500\pi t$ and $Y_2 = 2\, sin\, 506\, \pi t$ Number of beats produced per minute is
An aluminium rod having a length $100 \,cm$ is clamped at its middle point and set into longitudinal vibrations. Let the rod vibrate in its fundamental mode. The density of aluminium is $2600 \,kg / m ^3$ and its Young's modulus is $7.8 \times 10^{10} \,N / m ^2$. The frequency of the sound produced is .............. $Hz$
Two monoatomic ideal gases $1$ and $2$ of molecular masses $m_1$ and $m_2$ respectively are enclosed in separate containers kept at the same temperature. The ratio of the speed of sound in gas $1$ to that in gas $2$ is given by
Two adjacent piano keys are struck simultaneously. The notes emitted by them have frequencies ${n_1}$ and ${n_2}$. The number of beats heard per second is
Two wires $W_1$ and $W_2$ have the same radius $r$ and respective densities ${\rho _1}$ and ${\rho _2}$ such that ${\rho _2} = 4{\rho _1}$. They are joined together at the point $O$, as shown in the figure. The combination is used as a sonometer wire and kept under tension $T$. The point $O$ is midway between the two bridges. When a stationary waves is set up in the composite wire, the joint is found to be a node. The ratio of the number of an tin odes formed in $W_1$ to $W_2$ is
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
A man standing on a cliff claps his hand hears its echo after $1 \,sec$. If sound is reflected from another mountain and velocity of sound in air is $340\, m/sec.$ Then the distance between the man and reflection point is ..... $m$