2 Two parallel plates A and B are joined together to form a compound plate (figure 28-W3). The thicknesses of the plates are 40 cm and 2.5 cm respectively and the area of cross section is 100 cm for each plate. The thermal conductivities are K= 200 W m C for the plate A and K-400 W m C for the plate B. The outer surface of the plate A is maintained at 100C and the outer surface of the plate B is maintained at 0C. Find (a) the rate of heat flow through any cross section, (b) the temperature at the interface and (c) the equivalent thermal conductivity of the compound plate. 100C A B 0C Figure 28-W3