If the phase difference between two waves is $2\pi$ during superposition,then the resultant amplitude is

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

Two waves of the same frequency and same amplitude $a$ are superimposed. If the resultant amplitude is also $a$,what is the phase difference between the two waves?

Two pulses in a stretched string whose centres are initially $8 \ cm$ apart are moving towards each other as shown in the figure. The speed of each pulse is $2 \ cm/s$. After $2 \ seconds$,the total energy of the pulses will be

Two waves of same frequency and intensity superimpose with each other in opposite phases,then after superposition the

The displacement of an elastic wave is given by the function: $y = 3\, \sin\, \omega t + 4\, \cos\, \omega t$,where $y$ is in $cm$ and $t$ is in $s$. The resultant amplitude is ...... $cm$.