Two harmonic travelling waves are described by the equations $y_1 = a \sin (kx - \omega t)$ and $y_2 = a \sin (-kx + \omega t + \phi)$. The amplitude of the superposed wave is:

Two waves are superimposed whose ratio of intensities is $9: 1$. The ratio of maximum and minimum intensity is

The amplitude and phase of a wave that is formed by the superposition of two harmonic travelling waves,$y_1(x, t) = 4 \sin(kx - \omega t)$ and $y_2(x, t) = 2 \sin(kx - \omega t + \frac{2\pi}{3})$,are (Take the angular frequency of initial waves same as $\omega$):

Two sound waves of intensity $2 \, W/m^2$ and $3 \, W/m^2$ meet at a point to produce a resultant intensity $5 \, W/m^2$. The phase difference between the two waves is ......

If two waves of the same frequency and same amplitude,on superimposition,produce a resultant disturbance of the same amplitude,the phase difference between the waves is

The sources of sound $A$ and $B$ produce a wave of $350 Hz$ in the same phase. $A$ particle $P$ is vibrating under the influence of these two waves. If the amplitudes at $P$ produced by the two waves are $0.3 mm$ and $0.4 mm$,the resultant amplitude of the point $P$ will be,when $AP-BP=25 cm$ and the velocity of sound is $350 m s^{-1}$. (in $mm$)