SSC MTS EXAM

Detailed explanation-1: -The liquid in the thermometer goes up when the thermometer is heated because heating makes the alcohol molecules of the liquid move faster. The extra speed of the molecules competes with their attraction for one another and causes them to move slightly further apart.

Detailed explanation-2: -In general, the liquids tend to expand when their temperature increases. For example, the same mass of boiling water occupies more volume at 100 degrees Celsius than at 20 degrees Celsius. Therefore, increasing temperature decreases density.

Detailed explanation-3: -The expansion of alcohol in a thermometer is one of many commonly encountered examples of thermal expansion, which is the change in size or volume of a given system as its temperature changes.