Two rods of different materials are matained at the same temperature different at their ends. Their lenghts are l_(1),l_(2) cross sectionalareas are A_(1),A_(2)and coeffcients of thermal conductivity are K_(1),K_(2) . If the heat at the steady state is same in both the rods, what condition should be satisfied ?

Two rods of different materials are matained at the same temperature d

1.	Two rods of different materials are matained at the same temperature different at their ends. Their lenghts are l_(1),l_(2) cross sectionalareas are A_(1),A_(2)and coeffcients of thermal conductivity are K_(1),K_(2) . If the heat at the steady state is same in both the rods, what condition should be satisfied ?
Answer» Solution :Rate of FLOW of heat means Q/t., Given`(Q)/(t) = (K_(1)A_(1)(d THETA))/(l_(1)) = (K_(2)A_(2)(d theta))/(l_(2)) rArr (l_(1))/(K_(2)A_(2))`, i.e.,their thermal resistanceare the sameIf `l_(1)- l_(2)`then `K_(1)A_(1) = K_(2)A_(2) ,`If `A_(1) = A_(2) ` then`K_(1)//K_(2) = l_(1)//l_(2)`