Context switch would occur if there is another process in the ready queue waiting for the processor. Since there aren't any hence the dispatcher will not be invoked, in other words no context switch occurs .. imo.
As for the second part, there would be 11 context switches considering the dispatching of the 1st process as a context switch from a previous process. P2 will execute for 4 seconds hence it will require two time quanta but context switch should not happen. .. again imo.