The phase difference between waves P and q in the diagram above is

Answer Details

From the given diagram, it can be observed that wave P reaches its maximum amplitude at time t=0, whereas wave Q reaches its maximum amplitude at time t=T/4. Since the time difference between the maximum points of the two waves is T/4, where T is the time period of the waves, we can say that the phase difference between waves P and Q is π/2 or 90 degrees. Therefore, the correct option is: π/2.