$A$ tuning fork of frequency $392 \, Hz$ resonates with $50 \, cm$ length of a string under tension $T$. If the length of the string is decreased by $2 \%$,keeping the tension constant,the number of beats heard when the string and the tuning fork are made to vibrate simultaneously is

An observer while going on a scooter hears the sound of two sirens of the same frequency from two opposite directions. If he travels along the direction of one of the sirens,then he:

$A$ tuning fork gives $3$ beats with $50 \ cm$ length of sonometer wire. If the length of the wire is shortened by $1 \ cm$,the number of beats is still the same. The frequency of the fork is (in $Hz$)

Two waves with amplitudes $3 \, m$ and $5 \, m$ produce beats. What is the ratio of the maximum to minimum intensity?

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 vibrating tuning forks produce progressive waves given by ${y_1} = 4\,\sin \left( {500\pi t} \right)$ and ${y_2} = 2\,\sin \left( {506\pi t} \right)$. These tuning forks are held near the ear of a person. The person will hear $\alpha \, \text{beats/s}$ with intensity ratio between maxima and minima equal to $\beta$. Find the value of $\beta - \alpha$.