A brass rod (thermal conductivity 109 J/s m K) has an area of cross section 0.04 m2 and length 20 cm. If the two end of the rod are maintained at a temperature difference of 200°C, the rate of heat flow through the rod is ________.
1
3.42 kJ/s
2
2.32 kJ/s
3
4.36 kJ/s
4
5.80 kJ/s