A clinical thermometer is usually much shorter than a laboratory thermometer, because

Options

A. only a limited range of temperature is required
B. it is marked in Fahrenheit and not in Celsius
C. a long column is inconvenient
D. a long column of mercury can not be introduced in glass tube

Answer

To solve the question regarding why a clinical thermometer is usually much shorter than a laboratory thermometer, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Purpose of Thermometers**:
- Clinical thermometers are designed for measuring body temperature, which typically ranges from about 35°C to 42°C (or 95°F to 107.6°F).
- Laboratory thermometers, on the other hand, are used for a wider range of temperatures, often from -10°C to 110°C or even higher.

2. **Determining the Required Temperature Range**:
- Since clinical thermometers are used in medical settings, they only need to measure a limited range of temperatures accurately. This is usually from around 35°C to 42°C.
- Laboratory thermometers need to cover a much broader range of temperatures, which can extend from sub-zero temperatures to several hundred degrees Celsius.

3. **Length of the Thermometer**:
- Given the limited range of temperatures that clinical thermometers need to measure, they can be shorter in length. A shorter thermometer is easier to handle and store in a clinical environment.
- In contrast, laboratory thermometers need to be longer to accommodate the larger range of temperatures they measure.

4. **Evaluating the Options**:
- **Option 1**: "Only a limited range of temperature is required." - This is correct because clinical thermometers are designed for a specific temperature range.
- **Option 2**: "It is marked in Fahrenheit and not in Celsius." - This is incorrect; clinical thermometers can be marked in both scales.
- **Option 3**: "A long column is inconvenient." - This is subjective and not the primary reason for the difference in length.
- **Option 4**: "A long column of mercury cannot be introduced in glass tube." - This is incorrect; a long column of mercury can be introduced.

5. **Conclusion**:
- The correct answer is that clinical thermometers are shorter because they are designed to measure only a limited range of temperature.

### Final Answer:
A clinical thermometer is usually much shorter than a laboratory thermometer because only a limited range of temperature is required.

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