by Maryam Hussain How the working of a theoretical engine was proposed? The theoretical heat engine was proposed by Sadi Carnot in 1824 . Heat engines are devices that can convert heat into mechanical energy. Like a Steam engine or Motor vehicle, the working principle of all heat engines is the same in which any working substance gas or vapor is brought back to the initial stage by going through different thermodynamic stages of a cyclic process . Carnot suggested that, if a heat engine goes through fixed thermodynamic stages of a specified process, then the efficiency of the heat engine may be 100% possible. Ideally, this engine gives maximum efficiency. No other engine can be more efficient than this. The specified cyclic process suggested by Carnot is called the Carnot cycle. The Carnot engine has four main parts: 1). First, an insulated, non-conducting stand , so that the transfer of energy is not possible . 2). Second, a hot reservoir with infi...
by Maryam Hussain How does air become humid and dry? When the air remains in contact with a water surface then it gets the vapor from water because of the continuous evaporation of water in the air above it. The extent of the evaporation rate is a function of the vapor pressure of water at the present temperature of the water. When the quantity of vapors of the water in the air is such that the partial pressure of vapors in the air equals the vapor pressure of the water at its existing temperature then an equilibrium is said to be reached between the two pressures and the gas is said to be saturated with this vapor. It is not possible for the air to contain a greater stable concentration of water vapor, because as soon as the vapor pressure of the water is exceeded by the partial pressure of the water vapor, condensation takes place . When the air contains water vapor then it is called moist air or humid air. When the air contains water vapor in such p...