A flow field which has only convective acceleration is

As the temperature increases, the thermal conductivity of a gas

A plane wall has a thermal conductivity of $$1.15$$ $$W/m.K.$$ If the inner surface is at $${1100^ \circ }C$$ and the outer surface is at $${350^ \circ }C$$, then the design thickness (in meter) of the wall to maintain a steady heat flux of $$2500\,\,W/{m^2}$$ should be ____________.

Match Group $$A$$ with Group $$B$$

Group-A
$$P:$$$$\,\,\,\,\,\,\,$$ Biot number
$$Q:$$$$\,\,\,\,\,\,\,$$ Grashof number
$$R:$$$$\,\,\,\,\,\,\,$$ Prandtl number
$$S:$$$$\,\,\,\,\,\,\,$$ Reynolds number

Group-B
$$1:$$$$\,\,\,\,\,\,\,$$ Ratio of buoyancy to viscous force
$$2:$$$$\,\,\,\,\,\,\,$$ Ratio of inertia force to viscous force
$$3:$$$$\,\,\,\,\,\,\,$$ Ratio of momentum to thermal diffusivities
$$4:$$$$\,\,\,\,\,\,\,$$ Ratio of internal thermal resistance to boundary layer thermal resistance