______ is measured using an instrument called a U-tube manometer.

Options

A. Liquid pressure
B. Atmospheric pressure
C. Gravitational force
D. Force

Answer

To solve the question, "______ is measured using an instrument called a U-tube manometer," we need to identify what type of pressure is measured by this instrument.

### Step-by-Step Solution:

1. **Understanding the U-tube Manometer**:
- A U-tube manometer is a device that consists of a U-shaped tube filled with liquid, usually mercury or water. It is used to measure the pressure of liquids.

2. **Identifying the Type of Pressure**:
- The U-tube manometer is specifically designed to measure the pressure exerted by a liquid column. This pressure can be due to the weight of the liquid itself or any external pressure applied to it.

3. **Analyzing the Options**:
- The options provided are:
- Liquid Pressure
- Atmospheric Pressure
- Gravitational Force
- Force
- Among these options, "Liquid Pressure" is the most relevant as the U-tube manometer is primarily used to measure the pressure of liquids.

4. **Conclusion**:
- Therefore, the correct answer to the question is "Liquid Pressure".

### Final Answer:
**Liquid Pressure**