An air column inside a straight pipe can sustain stationary waves when suitably excited.
(a) With the help of neatly labelled sketches, depict the standing-wave patterns for (i) the fundamental mode and (ii) the first two overtones produced in a pipe open at both ends of length L.
(b) Repeat part (a) for a pipe of the same length but closed at one end.
(c) Giving reason based on the boundary conditions that exist at the ends of a closed pipe, explain why only odd-numbered harmonics are possible in such a pipe.