Sound Reflection in Open Pipe – Rankers Physics

Standing Wave in String and Organ Pipe: Practice Problem & Solution

Assertion (A): When a high pressure pulse of air travelling down an open pipe reaches the other end, turns into a pulse of low pressure pulse travelling up the tube. Reason (R): Node of pressure means antinode of displacement in case of open pipe.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Standing Wave in String and Organ Pipe. Understanding the underlying formula is key to arriving at the correct answer below:

At an open end, the pressure must remain atmospheric, establishing a pressure node. An incident high pressure pulse reflects as a low pressure pulse ((pi) phase change) to maintain this. Thus (A) is true. At a pressure node, particles have maximum displacement, which is a displacement antinode. Thus (R) is true and explains the reflection in (A).

Leave a Reply

Your email address will not be published. Required fields are marked *

Similar Practice Questions

Explore conceptually related problems to test your knowledge.

1. Two sources are said to be coherent if they
2. A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distance of $2text{ m}$ and $3text{ m}$ respectively from the source. The ratio of the intensities of the waves at P and Q is: (2005)
3. Assertion (A): Sound waves cannot propagate through vacuum but light waves can. Reason (R): Sound waves cannot be polarised but light waves can be.  
4. Assertion (A): Transverse mechanical waves cannot be generated within the volume of liquids. Reason (R): Liquids does not have modulus of rigidity.  
5. The length of a sonometer wire AB is $110 \text{ cm}$. Where should the two bridges be placed from A to divide the wire in 3 segments whose fundamental frequencies are in the ratio of $1:2:3$? (1995)