what is convection and radiation
Answers
Answer:
Conduction is the transfer of thermal energy through direct contact. Convection is the transfer of thermal energy through the movement of a liquid or gas. Radiation is the transfer of thermal energy through thermal emission. Hope this helps!
What is Convection?
Convection is defined as : The movement of fluid molecules from higher temperature regions to lower temperature regions.
Convection Equation
As the temperature of the liquid increases, the liquid’s volume also has to increase by the same factor and this effect is known as displacement. The equation to calculate the rate of convection is as follows:
- Q = hc ∙ A ∙ (Ts – Tf)
What is Radiation?
Thermal radiation is generated by the emission of electromagnetic waves . These waves carry away the energy from the emitting body. Radiation takes place through a vacuum or transparent medium which can be either solid or liquid. Thermal radiation is the result of the random motion of molecules in the matter. Movement of charged electrons and protons is responsible for the emission of electromagnetic radiation.
Radiation Equation
As temperature rises, the wavelengths in the spectra of the radiation emitted decreases and shorter wavelengths radiations are emitted. Thermal radiation can be calculated by Stefan-Boltzmann law:
- P = e ∙ σ ∙ A· (Tr – Tc)4