Q. A solid cylinder of radius R made of a material of thermal conductivity
K1 is surrounded by a cylindrical shell of inner radius R and outer radius
2R made of a material of thermal conductivity
K2. The two ends of the combined system are maintained at two different temperatures. Then there is no loss of heat across the cylindrical surface and the system is in steady state. The effective thermal conductivity of the system is:
- 4K1+3K24
- 3K1+4K24
- 3K1+K24
- K1+3K24