A common hydrometer reads specific gravity of liquids Compared to the 1.6 mark of the stem the mark 1.5 will be

Options

A. upwards
B. downwards
C. in the same place
D. may be upward or downward depending upon the hydrometer

Explanation

To solve the problem, we need to understand how a hydrometer works and how it indicates the specific gravity of liquids.

### Step-by-Step Solution:

1. **Understanding the Hydrometer**: A hydrometer is an instrument used to measure the specific gravity (density relative to water) of liquids. It consists of a weighted bulb and a graduated scale.

2. **Principle of Operation**: The hydrometer floats in the liquid, and the level at which it floats indicates the specific gravity. According to Archimedes' principle, the buoyant force acting on the hydrometer is equal to the weight of the liquid displaced by it.

3. **Specific Gravity Reading**: The specific gravity is read from the scale on the hydrometer. If the liquid is less dense than water, the hydrometer will sink lower, causing the reading to be higher on the scale (closer to zero). Conversely, if the liquid is denser than water, the hydrometer will float higher, resulting in a lower reading on the scale.

4. **Comparing the Marks**: In the question, we are asked to compare the mark at 1.6 with the mark at 1.5. If the hydrometer is floating in a liquid that has a specific gravity less than 1.6, the hydrometer will sink lower, causing the reading to rise (the mark at 1.5 will be above the surface of the liquid).

5. **Conclusion**: Since the question asks where the mark 1.5 will be compared to the mark 1.6 when the hydrometer is in a liquid, and we know that a lower specific gravity causes the hydrometer to float higher, we conclude that the mark 1.5 will be upwards compared to the mark 1.6.

Thus, the answer is **A. Upwards**.