Two identical metal balls one at `T_(1)=300K` and the other `T_(2)=600K` are kept at a distance of 1m in vacuum. Will the temperatures equalize by radiation? Will the rate of heat gained by the colder sphere be proportional to `T_(2)^(4)-T_(1)^(4)` as may be expected from the Stefan's law ?

The figure shows a system of two concentric spheres of radii r_1 and r_2 are kept at temperature T_1 and T_2 , respectively. The radial rate of flow of heat in a substance between the two concentric spheres is proportional to

A black body, at temperature T K emits radiation at the rate of 81 W/m2. It the temperature falls to t=T/3 K. then the new rate of thermal radiation will be

A solid at temperature T_(1) is kept in an evacuated chamber at temperature T_(2)gtT_(1) . The rate of increase of temperature of the body is propertional to

The figure shows a system of two concentric spheres of radii r 1 ​ and r 2 ​ and kept at temperature T 1 ​ and T 2 ​ , respectively. The radial rate of flow of heat in a substance between the two concentric spheres, is proportional to:

Two conducting cylinders of equal length but different radii are connected in series between two heat baths kept at temperatures T_(1) = 300K and T_(2) = 100 K , as shown in the figure. The radius of the bigger cylinder is twice that of the smaller one and the thermal conductivities of the materials of the smaller and the larger cylinders are K_(1) and K_(2) respectively. If the temperature at the junction of the two cylinders in the steady state is 200 K, then K_(1)//K_(2)= __________.

Two walls of thickness d_(1) and d_(2) and thermal conductivites K_(1) and K_(2) are in contact. In the steady state, if the temperature at the outer surfaces are T_(1) and T_(2) the temperature at the common wall is

Two closed vessels of equal volume containing air at pressure P_(1) and temperature T_(1) are connected to each other through a narrow tube. If the temperature in one of the vessels is now maintained at T_(1) and that in the other at T_(2) , what will be the pressure in the vessels?

Two closed vessels of equal volume containing air at pressure P_(1) and temperature T_(1) are connected to each other through a narrow tube. If the temperature in one of the vessels is now maintained at T_(1) and that in the other at T_(2) , what will be the pressure in the vessels?

If K_(1)= Rate constant at temperature T_(1) and k_(2) rate constant at temperature T_(2) for a first order reaction, then which of the following relation is correct ?

The V - i graph for a conductor at temperature T_(1) and T_(2) are as shown in the figure. ( T_(2) - T_(1)) is proportional to