A person blows into open-end of a long pipe. As a result, a high pressure pulse of air travels down the pipe. When this pulse reaches the other end of the pipe,

Question

A person blows into open-end of a long pipe. As a result, a high pressure pulse of air travels down the pipe. When this pulse reaches the other end of the pipe, (A) a high-pressure pulse starts travelling up the pipe, if the other end of the pipe is open. (B) a low-pressure pulse starts travelling up the pipe, if the other end of the pipe is open. (C) a low-pressure pulse starts travelling up the pipe, if the other end of the pipe is closed. (D) a high-pressure pulse starts travelling up the pipe, if the other end of the pipe is closed

Tardigrade Admin · Accepted Answer

At the open end, the phase of a pressure wave changes by π radian due to reflection. At the closed end, there is no change in the phase of a pressure wave due to reflection.

Q. A person blows into open-end of a long pipe. As a result, a high pressure pulse of air travels down the pipe. When this pulse reaches the other end of the pipe,

a high-pressure pulse starts travelling up the pipe, if the other end of the pipe is open.

a low-pressure pulse starts travelling up the pipe, if the other end of the pipe is open.

a low-pressure pulse starts travelling up the pipe, if the other end of the pipe is closed.

a high-pressure pulse starts travelling up the pipe, if the other end of the pipe is closed

At the open end, the phase of a pressure wave changes by $π$ radian due to reflection. At the closed end, there is no change in the phase of a pressure wave due to reflection.