The two waves represented by $y_1 = a\,sin(\omega\,t)$ and $y_2 = b\, cos\, (\omega\, t)$ have a phase difference of

A pulse shown here is reflected from the rigid wall $A$ and then from free end $B.$ The shape of the string after these $2$ reflection will 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 .... $m$

In a Fraunhofer's diffraction obtained by a single slit aperture, the value of path difference for $n^{th}$ order of minima is

A point source emits sound equally in all directions in a non-absorbing medium. Two points $P$ and $Q$are at distances of $2m$ and $3m$ respectively from the source. The ratio of the intensities of the waves at $P$ and $Q$ is

A string $1\,m$ long is drawn by a $300\,Hz$ vibrator attached to its end. The string vibrates in three segments. The speed of transverse waves in the string is equal to ..... $m/s$