The equation of transverse wave in stretched string is $y = 5\,\sin \,2\pi \left[ {\frac{t}{{0.04}} - \frac{x}{{50}}} \right]$ Where distances are in cm and time in second. The wavelength of wave is .... $cm$

A train is moving towards a stationary observer. Which of the following curve best represents the frequency received by observer $f$ as a function of time ?

Two vibrating tuning forks produce 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

The velocities of sound at the same pressure in two monatomic gases of densities ${\rho _1}$ and ${\rho _2}$ are $v_1$ and $v_2$ respectively. ${\rho _1}/{\rho _2} = 2$, then the value of $\frac{{{v_1}}}{{{v_2}}}$ is

An 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 $P_2$ is

Two tuning forks $A$ and $B$ produce $8\, beats/s$ when sounded together. $A$ gas column $37.5\, cm$ long in a pipe closed at one end resonate to its fundamental mode  with fork $A$ whereas a column of length $38.5 \, cm$ of the same gas in a similar pipe  is required for resonance with fork $B$. The frequencies of these two tuning forks, are