Which of the following is NOT an example of application of Bernoulli's principle ?

Options

A. Venturimeter
B. Dynamic lift
C. Air purifier
D. Barometer

Answer

To determine which of the following is NOT an application of Bernoulli's principle, we will analyze each option provided in the context of Bernoulli's equation and its applications.

### Step-by-Step Solution:

1. **Understanding Bernoulli's Principle**:
Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in pressure or potential energy. It is often used in various applications involving fluid dynamics.

2. **Analyzing the Options**:
- **Venturimeter**: This device measures the flow rate of a fluid by utilizing the principle of conservation of energy, which is a direct application of Bernoulli's equation. As the fluid flows through a tube that narrows, its velocity increases, and the pressure decreases, allowing for flow rate measurement.

- **Dynamic Lift (e.g., Airplane Wings)**: The lift generated by airplane wings is due to the difference in air pressure above and below the wings, which is explained by Bernoulli's principle. Faster airflow over the wing results in lower pressure, creating lift.

- **Air Purifier**: An air purifier or exhaust fan works by increasing the velocity of air, which lowers the pressure in the area where the fan is located. This pressure difference allows contaminated air to be drawn in and replaced with cleaner air, which is also an application of Bernoulli's principle.

- **Barometer**: A barometer measures atmospheric pressure using a column of liquid (usually mercury) in a tube. It operates based on hydrostatic pressure rather than fluid dynamics described by Bernoulli's principle. The pressure exerted by the liquid column is due to the weight of the liquid and does not involve changes in fluid velocity.

3. **Conclusion**:
Based on the analysis, the device that is NOT an application of Bernoulli's principle is the **Barometer**.

### Final Answer:
**The barometer is NOT an application of Bernoulli's principle.**

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