Which of the following features are that of a clinical thermometer ?
A. Short temperature range B. Wide temperature range
C. Alcohol filled glass bulb D. Constriction in glass tube

Options

A. A and B
B. B and C
C. A and D
D. B and D

Answer

To determine the features of a clinical thermometer, we need to analyze each option provided in the question:

1. **Understanding the Temperature Range**:
- A clinical thermometer is designed to measure body temperature. It typically has a temperature range from 35 degrees Celsius to 42 degrees Celsius.
- This indicates that the thermometer can only measure temperatures within this limited range, which is considered a short temperature range.

**Conclusion**:
- Option A (Short temperature range) is correct.
- Option B (Wide temperature range) is incorrect.

2. **Identifying the Liquid in the Thermometer**:
- Clinical thermometers traditionally use mercury as the liquid in the glass bulb. While some modern thermometers might use alcohol, the classic clinical thermometer uses mercury.

**Conclusion**:
- Option C (Alcohol filled glass bulb) is incorrect.

3. **Examining the Structure of the Thermometer**:
- A clinical thermometer has a constriction in the glass tube. This constriction helps to hold the mercury in place after the thermometer is removed from the heat source, allowing for an accurate reading.

**Conclusion**:
- Option D (Constriction in glass tube) is correct.

### Final Answer:
The correct features of a clinical thermometer are:
- A. Short temperature range (Correct)
- C. Alcohol filled glass bulb (Incorrect)
- D. Constriction in glass tube (Correct)