The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:
The variation in temperature occurs between the two systems, and heat can be transferred from the higher to the lower. The various heat transmission modes include:
It is very pivotal to know the primary differences between boiling and evaporation. Evaporation is the transformation of moisture into vapour. Evaporation is a straightforward explanation of how water evaporates from the ground by light’s thermal action. On the other side, boiling is heating a liquid where the fluid temperature is higher than the material’s boiling point. The most significant major distinction between evaporation and boiling is that evaporation only occurs on the fluid’s surface when boiling happens over its vast mass.
Thermal expansion is a propensity for matter in response to a shift in temperature in shape, density and space. As the matter is heated, the kinetic energy of the molecules increases. The molecules then begin to vibrate and shift further and usually sustain a much more average separation. The low thermal expansion and the high thermal conductivity of a low-density material (without volume-producing improvements in the phase) are characteristics that improve its usage.
In contrast to volume, linear expansion means a transition in one dimension. The first estimate is linked to the shift in length dimensions in an object due to thermal expansion. The expansion means length shift or length rise. If the length transition over the volume occurs along a single dimension, the phenomenon is called linear expansion.
It happens due to the difference in temperature behind the expansion. It is, thus, implied that the temperature change reflects the expansion rate. Therefore, the concept of linear expansion explains how much substance can withstand whose original form and dimensions have changed due to heat radiation.
Volume expansion is known as the volume increase of the solids on heat, while surface expansion means the increase in the surface area of a solid on heating. Also, the surface expansion coefficient is defined as the ratio of increase in the area to its original area for each temperature increase.
The difference between solid and liquid expansion is linked to intermolecular forces that hold the substance together in the heating field. The constituent molecules for a solid substance are firmly connected due to intermolecular forces. It is also why solids have a specific form and length. If heated, these molecules absorb a certain amount of kinetic energy, start moving apart, and the expansion of materials is linear and volumetric.
Compared with a solid, the liquid’s molecules are not so intimately linked. These weakly bound molecules tend to move away from each other when heated. As the intermolecular forces are weaker, liquids expand faster than solids subjected to the same temperature rise.
The liquids and gases examples and real-world applications of expansion are as follows:
Liquids such as engine coolant or water follow a gradual discernible pattern of volume increase or decrease depending upon the subjected temperature. Unlike liquids, gases respond towards any temperature change at a greater rate due to their higher molecular kinetic energy. The application of volume expansion in gases can be witnessed in volume gas thermometers, where volume expansion is used to calibrate other thermometers.
Understanding heat transfer is essential for the development of heat energy systems. Coal-fired/gas-fired power plants are an example of these systems. Nuclear energy has been transformed into heat in nuclear power stations and produces steam to drive turbines.