1. | θ1=0, θ2=90 |
2. | θ1=10, θ2=85 |
3. | θ1=20, θ2=80 |
4. | θ1=30, θ2=100 |
Two rods of identical dimensions are joined end-to-end, and the ends of the composite rod are kept at 0∘C and 100∘C (as shown in the diagram). The temperature of the joint is found to be 40∘C. Assuming no loss of heat through the sides of the rods, the ratio of the conductivities of the rods K1K2 is:
1. | 32 | 2. | 23 |
3. | 11 | 4. | √3√2 |
Two rods A and B of different materials are welded together as shown in the figure. Their thermal conductivities are K1 and K2. The thermal conductivity of the composite rod will be:
1. | 3(K1+K2)2 | 2. | K1+K2 |
3. | 2(K1+K2) | 4. | (K1+K2)2 |