_{m} = (Δt_{1} - Δt_{2})/ log_{e} (Δt_{1}/Δt_{2})

_{m} = log_{e} (Δt_{1}/Δt_{2})/ (Δt_{1} - Δt_{2})

_{m} = t_{m} = (Δt_{1} - Δt_{2}) log_{e} (Δt_{1}/Δt_{2})

_{m} = log_{e} (Δt_{1} - Δt_{2})/ Δt_{1}/Δt_{2}

**Which of the following would lead to a reduction in thermal resistance?****A non-dimensional number generally associated with natural convection heat transfer is****The transfer of heat by molecular collision is known as****Sensible heat is the heat required to****Joule sec is the unit of****Which of the following statement is correct?****Kirchhoff's law states that****Heat is closely related with****The time constant of a thermocouple is****Moisture would find its way into insulation by vapour pressure unless it is prevented by****Radiation is the process of heat transfer in which heat flows from a ________, in a straight line, without…****When α is absorptivity, ρ is reflectivity and τ is transmissivity, then for a diathermanous…****According to Newton's law of cooling, the heat transfer from a hot body to a cold body is****The heat transfer by conduction through a thick sphere is given by****According to Stefan Boltzmann law, ideal radiators emit radiant energy at a rate proportional to****The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive…****When heat is transferred by molecular collision, it is referred to as heat transfer by****The energy distribution of an ideal reflector at higher temperatures is largely in the range of****The natural convection air cooled condensers are used in****The product of Reynolds number and Prandtl number is known as****The process of heat transfer from one particle of the body to another by the actual motion of the heated…****Sensible heat factor is given by (where S.H. = Sensible heat, and L.H. = Latent heat)****A heat exchanger with heat transfer surface area A and overall heat transfer coefficient U handles two…****The transfer of heat by molecular collision is smallest in****Fourier's law of heat conduction is valid for****The ratio of surface convection resistance to the internal conduction resistance is known as****Thermal diffusivity of a substance is****The unit of Stefan Boltzmann constant is****Thermal diffusivity is a****In case of liquids and gases, the heat transfer takes place according to**