Question

A pipe of length L is open at both ends. By blowing air across one end of the pipe, standing waves can be formed in the pipe. Which of the following statements are true?

It is possible for half a wavelength to fill the length of the pipe
The highest resonant frequency is called the fundamental
The middle of the pipe can never be a node or an antinode
When the pipe resonates, air molecules move back and forth perpendicular to the length of pipe
Each end of the pipe must be a node

Answer 1

statement 1 is true all are false

Fundamental

The longest standing wave in a tube of length L with two open ends has displacement antinodes (pressure nodes) at both ends. It is called the fundamental or first harmonic.so statement1 is true it is possible for half a wavelength to fill the length of the pipe 2) statement 2 is false because lowest resonant frequency is calleed fundmental 3) statement 3 is false middle of pipe be node or an antinode 4) Sound waves are longitudinal, i.e., the disturbance is parallel to propagation for them. In pipes, sound waves or disturbances travel parallel to the pipe's length.so statement 4 is wrong 5)At an open end, both nodes and antinodes can form. so statement 5 is wrong

Answer 2

First sdtatement is TRUE.