A thermometer is used to measure

Options

A. heat
B. thermal capacity
C. water equivalent
D. temperature

Answer

To solve the question "A thermometer is used to measure," we need to analyze the options provided: heat, thermal capacity, water equivalent, or temperature.

### Step-by-Step Solution:

1. **Understanding the Options**:
- **Heat**: This is a form of energy that is transferred between systems or objects with different temperatures (hot and cold).
- **Thermal Capacity**: This refers to the amount of heat required to change the temperature of a unit mass of a substance by one degree Celsius.
- **Water Equivalent**: This is the mass of water that would absorb the same amount of heat as the substance being measured, given the same temperature change.
- **Temperature**: This is a measure of the average kinetic energy of the particles in a substance, indicating how hot or cold the substance is.

2. **Identifying What a Thermometer Measures**:
- A thermometer is specifically designed to measure temperature. It does not measure heat, thermal capacity, or water equivalent directly.

3. **Conclusion**:
- Based on the definitions and the purpose of a thermometer, the correct answer is that a thermometer measures **temperature**.

### Final Answer:
A thermometer is used to measure **temperature**.

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