A closed organ pipe of length 1.2 m vibrates in its first overtone mode. The pressure variation is maximum at

Options

A. `0.4` m from the open end
B. `0.4` m from the closed end
C. Both (a) and (b)
D. `0.8` m from the open end

Answer

a

Explanation

In first overtone mode,
`l=(3lambda)/4 rArr lambda/4=l/3=1.2/3=0.4`m

Pressure variation will be maximum displacement nodes,
i.e. at `0.4` m from the open end.