If `T_(B)` and `T_(s)` are the temperatures of the body and the surroundings and `T_(B) -T_(s)` is of very high value, then the rate of cooling in natural convection is proportional to .

One end of rod of length L and cross-sectional area A is kept in a furance of temperature T_(1) . The other end of the rod is kept at at temperature T_(2) . The thermal conductivity of the material of the rod is K and emissivity of the rod is e . It is given that T_(2)=T_(S)+DeltaT where DeltaT lt lt T_(S) , T_(S) being the temperature of the surroundings. If DeltaT prop (T_(1)-T_(S)) , find the proportionality constant. Consider that heat is lost only by radiation at the end where the temperature of the rod is T_(2) .

One end of rod of length L and cross-sectional area A is kept in a furance of temperature T_(1) . The other end of the rod is kept at at temperature T_(2) . The thermal conductivity of the material of the rod is K and emissivity of the rod is e . It is given that T_(2)=T_(S)+DeltaT where DeltaT lt lt T_(S) , T_(S) being the temperature of the surroundings. If DeltaT prop (T_(1)-T_(S)) , find the proportionality constant. Consider that heat is lost only by radiation at the end where the temperature of the rod is T_(2) .

One end of rod of length L and cross-sectional area A is kept in a furance of temperature T_(1) . The other end of the rod is kept at at temperature T_(2) . The thermal conductivity of the material of the rod is K and emissivity of the rod is e . It is given that T_(2)=T_(S)+DeltaT where DeltaT lt lt T_(S) , T_(S) being the temperature of the surroundings. If DeltaT prop (T_(1)-T_(S)) , find the proportionality constant. Consider that heat is lost only by radiation at the end where the temperature of the rod is T_(2) .

A very thin metallic shell of radius r is heated to temperature T and then allowed to cool. The rate of cooling of shell is proportional to

A very thin metallic shell of radius r is heated to temperature T and then allowed to cool. The rate of cooling of shell is proportional to

One end of a rod of length L and crosssectional area A is kept in a furnace at temperature T_(1) . The other end of the rod is kept at a temperature T_(2) . The thermal conductivity of the matrieal of the rod is K and emissivity of the rod is e. It is gives that T_(!)=T_(s)+DeltaT , where DeltaTltlt T_(s),T_(s) is the temperature of the surroundings. If DeltaTprop(T_(1)-T_(2)) find the proportional constant, consider that heat is lost only by rediation at the end where the temperature of the rod is T_(1) .