Answer : Option A
Thermal diffusivity =`(k)/(rho C_p)`
k is thermal conductivity (W/(mK).
`rho` is density (kg/m3).
`C_p` is specific heat capacity (J/(kgK)).
Harmonic mean temperature difference is given by
Answer : Option B
Graetz number is given by
Grashoff number, which is defined as g .`beta(T_s - T_oo ) rho^2. L^3// mu^2` is proportional to the ratio of buoyancy force to __________ force.
In thermal radiation for a black body (where,` epsi` is emissivity and `alpha` is absorptivity)
Answer : Option D