Question

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

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

Answer 1

The correct option is A upwards

The hydrometer works on the principle that a floating body displaces a volume of liquid whose weight is equal to its own; the lighter the liquid (that is, the less its specific gravity), the deeper the hydrometer sinks because a greater amount of liquid is required to equal the body's weight. Hence $1.5$ mark should be above $1.6$ So correct option is A.