Fig 4.3 (a-d) shows a student reading a doctor's thermometr. Which of the figure indicates the correct method of reading temperature ?

Options

A.
B.
C.
D.

Answer

To determine which figure indicates the correct method of reading a doctor's thermometer, we will analyze each option based on the guidelines for proper thermometer usage.

### Step-by-Step Solution:

1. **Understanding the Thermometer**: A thermometer measures temperature using mercury or alcohol that expands and contracts with temperature changes. It is crucial to read it correctly to get an accurate measurement.

2. **Key Guidelines for Reading a Thermometer**:
- **Do Not Hold the Bulb**: Holding the bulb can warm the mercury with your body heat, leading to an inaccurate reading.
- **Keep the Thermometer Vertical**: Tilting the thermometer can cause the mercury to fall, resulting in a lower reading than the actual temperature.
- **Eye Level Reading**: The thermometer should be held at eye level to ensure that the reading is clear and accurate.

3. **Analyzing Each Option**:
- **Option 1**: The student is not holding the bulb, the thermometer is vertical, and it is positioned at eye level. This option follows all the guidelines correctly.
- **Option 2**: The thermometer is tilted, which can cause the mercury to fall. This option does not follow the guidelines and is incorrect.
- **Option 3**: The thermometer is held straight, but it is below eye level, making it difficult to read accurately. This option is also incorrect.
- **Option 4**: The student is holding the bulb with their hand, which can warm the mercury. This option is incorrect as well.

4. **Conclusion**: Based on the analysis, **Option 1** is the only figure that indicates the correct method of reading a doctor's thermometer.

### Final Answer:
The correct method of reading the temperature is shown in **Option 1**.

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