A transverse wave is described by the equation $y = {y_0}\sin 2\pi \left( {ft - \frac{x}{\lambda }} \right)$. The maximum particle velocity is equal to four times wave velocity if
$\lambda = \frac{{\pi {y_0}}}{4}$
$\lambda = \frac{{\pi {y_0}}}{2}$
$\lambda = \pi {y_0}$
$\lambda = 2\pi {y_0}$
Fundamental frequency of a sonometer wire is $n$ . If the length and diameter of the wire are doubled keeping the tension same, then the new fundamental frequency is
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
An engine approaches a hill with a constant speed. When it is at a distance of $0.9 km$ it blows a whistle, whose echo is heard by the driver after $5$ sec. If speed of sound in air is $330 m/s$, the speed of engine is .... $m/s$
Two trains $A$ and $B$ initially $120\, km$ apart, start moving towards each other on the same track with a velocity of $60\, km/hr$ each. At the moment of start $A$ blows a whistle, which reflects on $B$ and subsequently reflects from $A$ and so on. Take the velocity of sound waves in air $1200\, km/hr$. The distance travelled by sound waves before the trains crash will be (in $km$)
Dependence of disturbances due to two waves on time is shown in the figure. The ratio of their intensities $I_1 / I_2$ will be