A composite hollow sphere with steady internal heating is made of 2 layers of materials of equal thickness with thermal conductivities in the ratio of 1:2 for inner to outer layers. Ratio of inside to outside diameter is 0.8. What is ratio of temperature drop across the Inner and outer layers? (IES-05)
a. 0.4 b. 1.6
c. 2 in 0.8 d. 2.5