A heat source at T = 103 K is connected to another heat reservoir at T = 102 K by a copper slab which is 1 m thick. Given that the thermal conductivity of copper is 0.1 WK–1 m–1, the energy flux through it in the steady state is :
(1) 120 Wm–2
(2) 65 Wm–2
(3) 200 Wm–2
(4) 90 Wm–2