If two waves having amplitudes $2A$ and $A$ and same frequency and velocity,propagate in the same direction in the same phase,the resulting amplitude will be

The superposition takes place between two waves of frequency $f$ and amplitude $a$. The total intensity is directly proportional to

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 ......

Two identical harmonic pulses travelling in opposite directions in a taut string approach each other. At the instant when they completely overlap,the total energy of the string will be

Two waves of amplitudes $A_1$ and $A_2$ respectively are superimposed. The ratio between the maximum and minimum intensities of the resultant waves is $9 : 4$. The value of $A_2 / A_1$ is [Assume $A_1 > A_2$]

Two waves $Y_1 = a \sin \omega t$ and $Y_2 = a \sin (\omega t + \delta)$ produce interference. The resultant intensity is ......