Question

If we study the vibration of a pipe open at both ends, then which of the following statements is not true?

Options

• Open end will be anti-node.

• Odd harmonics of the fundamental frequency will be generated.

• All harmonics of the fundamental frequency will be generated.

• Pressure change will be maximum at both ends.

Answer 1

Pressure change will be maximum at both ends.

Explanation:

The air column in a pipe open at both ends can vibrate in a number of different modes subjected to the boundary condition that there must be an antinode at the open end. Hence option (A) is correct.

The ratio of frequency when pipe is open at both the ends is given as, n : 2n : 3n : 4n : 5n

`"where n" = "v"/(2"L")`

∴ Both odd as well as even i.e., all harmonics are present.

Hence, option (B) and (C) are correct.

Pressure variation is minimum at antinode

∴ Option (D) is incorrect.