Figure shows an aluminium rod joined to a copper rod. Each of the rods has a length of 20cm and area of ccross section `0.20cm^(2)` . The junction is maintained at a constant temperature `40^(@)C` and the two ends are maintained at 80^(@)C` . Calculate the amount of heat taken out from the cold junction in one minute after the steady state is reached. The conductivities are `K_(Al)=200Wm^(-1)`^(@)C^(-1)` . and `K_(Cu)=400Wm^(-1)`^(@)C^(-1)` .