A closed cubical box made of perfectly insulating material

Last updated: 6/8/2023

A closed cubical box made of perfectly insulating material has walls of thickness 8 cm and the only way for heat to enter or leave the box is through two solid metal plugs A and B each of cross sectional area 12 cm and length 8 cm fixed in the opposite walls of the box as shown in the figure Outer surface A is kept at 100 C while the outer surface A is kept at 4 C The thermal conductivity of the material of the plugs is 0 5 cals cm C A source of energy generating 36 cals 1 is enclosed inside the box The equilibrium temperature of the inner surface of the box assuming that it is same at all points on the inner surface is 100 C A B 4 C