An open organ pipe of length l vibrates in its fundamental mode. The pressure variation is maximum

Options

A. at the two ends
B. at the middle of the pipe
C. at distance L/4 inside the ends
D. at distance L/8 inside the ends

Answer

B

Explanation

In an open pipe the ends are points of displacement antinodes and hence pressure node. The midpoint (for fundamental mode) is a point of displacement node and hence pressure antinode. ( variation of pressure is maximum at pressure antinode and zero at pressure -node).