Which of the following device is used to measure the rate of liquid through a pipe ?

Options

A. Thermometer
B. Barometer
C. Manometer
D. Venturimeter

Answer

To determine which device is used to measure the rate of liquid flowing through a pipe, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Flow Rate**:
- The flow rate of a liquid is defined as the volume of liquid that passes through a given surface per unit time. It is typically measured in units such as liters per second (L/s) or cubic meters per second (m³/s).

2. **Identify the Devices Listed**:
- The question provides a list of devices: thermometer, barometer, manometer, and Venturi meter.

3. **Analyze Each Device**:
- **Thermometer**: This device measures temperature, not flow rate.
- **Barometer**: This device measures atmospheric pressure, not flow rate.
- **Manometer**: This device is used to measure the pressure of gases or liquids, not flow rate.
- **Venturi Meter**: This device is specifically designed to measure the flow rate of liquids through a pipe by utilizing the principle of fluid dynamics.

4. **Conclusion**:
- Based on the analysis, the Venturi meter is the correct device used to measure the rate of liquid flowing through a pipe.

### Final Answer:
- The device used to measure the rate of liquid through a pipe is the **Venturi meter**.

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