Two monoatomic ideal gases $1$ and $2$ of molecular masses $M_1$ and $M_2$ respectively are enclosed in separate containers kept a the same temperature. The ratio of the speed of sound in gas $1$ to that in gas $2$ is
$\sqrt {\frac{{{M_1}}}{{{M_2}}}} $
$\sqrt {\frac{{{M_2}}}{{{M_1}}}} $
$\frac{{{M_1}}}{{{M_2}}}$
$\frac{{{M_2}}}{{{M_1}}}$
A stretched wire of length $110\,cm$ is divided into three segments whose frequencies are in ratio $1 : 2 : 3.$ Their lengths must be
A transverse harmonic wave on a string is described by $y = 3\sin \left( {36t + 0.018x + \frac{\pi }{4}} \right)$ where $x$ and $y$ are in $cm$ and $t$ in $s$. The least distance between two successive crests in the wave is .... $m$
A wave travelling along the $x-$ axis is described by the equation $y \,(x, t ) = 0.005\, cos \,\left( {\alpha x - \beta t} \right)$. If the wavelength and the time period of the wave are $0.08\,m$ and $2.0\, s$ respectively then $a$ and $b$ in appropriate units are
A small source of sound moves on a circle as shown in the figure and an observer is standing on $O.$ Let $n_1,\, n_2$ and $n_3$ be the frequencies heard when the source is at $A, B$ and $C$ respectively. Then
A train approaching a railway plateform with a speed of $20\,\,m\,s^{-1}$ starts blowing the whistle speed of sound in air is $340\,\,ms^{-1}.$ If frequency of the emitted sound from the whistle is $640\,\,Hz,$ the frequency of sound as heard by person standing on the platform is .... $Hz$