Question

Apparent expansion of the liquid is its expansion relative to the___________.

Answer 1

To answer this question we should first understand expansion and the concept of real expansion and the apparent expansion. Also, we should try to understand the stepwise expansion process which occurs when we heat any liquid in any container. Different materials have different expansion rates and should always be kept in mind while answering the question.

Complete step by step answer:
To answer this question we should start with the basics i.e., expansion.

Expansion or here thermal expansion is the response of any material with the response to rising in the surrounding material. Different materials have different rates of expansion. The amount of expansion in any substance depends on the temperature difference and the coefficient of thermal expansion of that substance. Different substances have different coefficients of thermal expansion.

When we heat a liquid kept inside a container, the liquid heats up through the container. The container also has some coefficient of thermal expansion. So while heating the liquid, the container also undergoes volumetric expansion. Due to this the original level of the liquid changes. After getting heated, the water also expands. Thus the expansion so obtained is the apparent expansion. The actual expansion in the liquid is more than what is observed. Thus we can say that,
Real expansion of a liquid $=$ Real expansion of a liquid $+$ volume expansion of the container

Hence we can say that apparent expansion of the liquid is its expansion relative to the volume expansion of the container.

So the answer will be volume expansion of the container.

Note: Expansion is a very important phenomenon. It cannot be ignored and it is clearly evident from the above heating of a liquid in a container example. Other common uses of the phenomena of expansion are the use of mercury or alcohol in thermometers, joints in rail tracks, adjustment of clocks in winter, etc.