You have 2 pipes of length 1.20 m. One pipe is open, other has one end closed. First overtone is formed in both the pipes. Find the position of 1st displacement node from origin
0.3 m, 0.4 m
First overtone pressure plot
Displacement plot
For the open pipe, first displacement node is formed at : L4=1.24=0.3 m
For the closed pipe, first displacement node is formed at : L3=1.23=0.4 m