SSC MTS EXAM

Detailed explanation-1: -When the temperature of an object is raised, its particles move around more, so they take up more space. This causes the entire object to expand. The thermal expansion causes the density of a substance to decrease because the same mass takes up more volume.

Detailed explanation-2: -The increase in volume of substance with increasing temperature is called expansion.

Detailed explanation-3: -Thermal expansion is caused by heating solids, liquids or gases, which makes the particles move faster or vibrate more (for solids). This means that the particles take up more space and so the substance expands.

Detailed explanation-4: -Thermal expansion is the tendency of matter to change in shape, volume, and area in response to a change in temperature. Temperature is a monotonic function of the average molecular kinetic energy of a substance.