Cohesive force of water molecules is of the magnitude of (Dixon and Joly )

Options

A. 1-10 atm
B. 10-15 atm
C. 45-200 atm
D. 15-45 atm

Answer

To solve the question regarding the cohesive force of water molecules as described by Dixon and Joly, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Cohesive Force**:
- Cohesive force refers to the attraction between water molecules, which allows them to stick together. This property is crucial for the movement of water in plants, particularly in the xylem.

2. **Definition of Tensile Strength**:
- The cohesive force can also be described as the tensile strength of water. It is the maximum amount of tension that a liquid can withstand before breaking.

3. **Reference to Dixon and Joly**:
- Dixon and Joly conducted experiments that quantified the cohesive force of water in the context of plant physiology. They found that the cohesive strength of water in the xylem sap is significant.

4. **Magnitude of Cohesive Force**:
- According to the findings, the cohesive force of water molecules is approximately between 47 to 207 atmospheric pressure.

5. **Identifying the Correct Option**:
- Given the options:
1. 1 to T
2. 10 atmospheric pressure
3. 10 to 15 atmospheric pressure
4. 45 to 200 atmospheric pressure
5. 15 to 45 atmospheric pressure
- The range of 45 to 200 atmospheric pressure is the closest to the measured value of 47 to 207 atmospheric pressure.

6. **Conclusion**:
- Therefore, the correct answer to the question is **45 to 200 atmospheric pressure**.

### Final Answer:
The cohesive force of water molecules is of the magnitude of **45 to 200 atmospheric pressure**.

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