Five rods of same dimensions are arranged as shown in the figure. They have thermal conductivities K1, K2, K3, K4 and K5. When points A and B are maintained at different temperatures, no heat flows through the central rod if [KCET 2002]

\[{{K}_{1}}{{K}_{2}}={{K}_{3}}{{K}_{4}}\]

\[{{K}_{1}}={{K}_{4}}\,\text{and}\,\ {{K}_{2}}={{K}_{3}}\]

\[{{K}_{1}}{{K}_{4}}={{K}_{2}}{{K}_{3}}\]

\[\frac{{{K}_{1}}}{{{K}_{4}}}=\frac{{{K}_{2}}}{{{K}_{3}}}\]

Five rods of same dimensions are arranged as shown in the figure. They

1.	Five rods of same dimensions are arranged as shown in the figure. They have thermal conductivities K1, K2, K3, K4 and K5. When points A and B are maintained at different temperatures, no heat flows through the central rod if [KCET 2002]
A.	\[{{K}_{1}}={{K}_{4}}\,\text{and}\,\ {{K}_{2}}={{K}_{3}}\]
B.	\[{{K}_{1}}{{K}_{4}}={{K}_{2}}{{K}_{3}}\]
C.	\[{{K}_{1}}{{K}_{2}}={{K}_{3}}{{K}_{4}}\]
D.	\[\frac{{{K}_{1}}}{{{K}_{4}}}=\frac{{{K}_{2}}}{{{K}_{3}}}\]
Answer» C. \[{{K}_{1}}{{K}_{2}}={{K}_{3}}{{K}_{4}}\]