Regarding an open organ pipe , which of the following is correct?

Options

A. Both the ends are pressure antinodes
B. Both the ends are displacement nodes
C. Both the ends are pressure nodes
D. Both (a) and (b)

Explanation

To solve the question regarding the characteristics of an open organ pipe, we will analyze the properties of sound waves in such a pipe. An open organ pipe is characterized by having both ends open, which affects the displacement and pressure nodes and antinodes.

### Step-by-Step Solution:

1. **Understanding Open Organ Pipes**:
- An open organ pipe has both ends open to the air. This means that at both ends, the air can move freely.

**Hint**: Remember that the ends of an open pipe are points where the air can vibrate freely.

2. **Displacement Nodes and Antinodes**:
- In terms of displacement, the open ends of the pipe are displacement antinodes. This means that at these points, the displacement of the air particles is at its maximum.

**Hint**: Displacement antinodes occur where the air moves the most, which is at the open ends of the pipe.

3. **Pressure Nodes and Antinodes**:
- Conversely, at the open ends, there are pressure nodes. This means that the pressure variation is minimal at these points, as the air can freely move in and out.

**Hint**: Pressure nodes occur where the pressure does not change significantly, which is at the open ends of the pipe.

4. **Analyzing the Options**:
- **Option 1**: Both ends are pressure antinodes. This is incorrect because both ends are pressure nodes.
- **Option 2**: Both ends are displacement nodes. This is incorrect because both ends are displacement antinodes.
- **Option 3**: Both ends are pressure nodes. This is correct as we established that both ends are indeed pressure nodes.
- **Option 4**: Both A and B. This is incorrect since both A and B are false.

5. **Conclusion**:
- The correct option is **Option 3**, which states that both ends are pressure nodes.

### Final Answer:
The correct statement regarding an open organ pipe is that **both ends are pressure nodes** (Option 3).