In complete English sentences Answer the five marked questio

What are the physical mechanisms associated with heat transfer by conduction, convection, and radiation? What . What is the driving potential for heat transfer? What are analogs to this poten- tial and to heat transfer itself for the transport of electric charge? . What is the difference between a heat flux and a heat rate? What are their units? What is a temperature gradient? What are its units? What is the relationship of heat flow to a temperature gradient? What is the thermal conductivity? What are its units? What role does it play in heat transfer? What is Fourier\'s law? Can you write the equation from memory? If heat transfer by conduction through a medium occurs under steady-state condi- tions, will the temperature at a particular instant vary with location in the medium? Will the temperature at a particular location vary with time? What is the difference between natural convection and forced convection? What conditions are necessary for the development of a hydrodynamic boundary layer? A thermal boundary layer? What varies across a hydrodynamic boundary layer? A thermal boundary layer? If convection heat transfer for flow of a liquid or a vapor is not characterized by liquid/vapor phase change, what is the nature of the energy being transferred? What is it if there is such a phase change? What is Newton\'s law of cooling? Can you write the equation from memory? hat role is played by the convection heat transfer coefficient in Newton\'s law of cooling? What are its units? What effect does convection heat transfer from or to a surface have on the solid ounded by the surface? What is predicted by the Stefan-Boltzmann law, and what unit of temperature must be used with the law? Can you write the equation from memory? What is the emissivity, and what role does it play in characterizing radiation transfer at a surface? What is irradiation, and what are its units? . What role is played by the convection heat What two outcomes characterize the response of an opaque surface to incident radiation? Which outcome affects the thermal energy of the medium bounded by the surface and how? What property characterizes this outcome?

Solution

1.Conduction-heat is transfer by lattice vibration (the faster moving molecules or atoms in the hottest part of a body transfer heat by impacts of their energy to adjacent molecules)

And

By transport of free electrons.

b.convection- heat transfer occurs since macroscopic particles of a fluid moving in space cause the heat exchange.

radiation-energy transfer occurs in the form of electromagnetic waves.

5. Thermal conductivity is the amount of energy conducted through a body of unit area , and unit thickness in unit time, when difference in temprature between the faces causesing heat flow in unit temprature difference.

Unit-watt/mkelvin or w/m.c

Role in heat transfer- it is a property of material , material with high thermal conductivity have higher amount of heat transfer .

Send remaining seprately too many questions in one.