Find the temperature distribution in the space between two coaxial cylinders of radii `R_1` and `R_2` filled with a uniform heat conducting substance if the temperatures of the cylinders are constant and are equal to `T_1` and `T_2` respectively.

Find the temperature distribution in a substance palced between two parallel plates kept at temperatures T_1 and T_2 . The plate separation is equal to l , the heat conductivity coefficient of the substance x overline prop V overline T .

A gas fills up the space between two long coaxial cylinders of radii R_1 and R_2 , with R_1 lt R_2 . The outer cylinder rotates with a fairly low angular velocity omega about the stationary inner cylinder. The moment of friction forces acting on a unit length of the inner cylinder is equal to N_1 . Find the viscosity coefficient eta of the gas taking into account that the friction force acting on a unit area of the cylindrical surface of radius r is determined by the formule sigma = eta r(del omega//del r) .

Calculate the capacitance per metre of a capacitor formed by two long coaxial cylinders of radii 5 and 5.2 cm filled with dielectric of permittivity 1.2.

Solve the foregoing problem for the case of two concentric spheres of radii R_1 and R_2 and temperatures T_1 and T_2 .

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 spherical black bodies of radii R_(1) and R_(2) and with surface temperature T_(1) and T_(2) respectively radiate the same power. R_(1)//R_(2) must be equal to

Two spherical black bodies of radii R_(1) and R_(2) and with surface temperature T_(1) and T_(2) respectively radiate the same power. R_(1)//R_(2) must be equal to

Two spherical black bodies of radii R_(1) and R_(2) and with surface temperature T_(1) and T_(2) respectively radiate the same power. R_(1)//R_(2) must be equal to