The temperature difference between the upper layers and the deeper layers of the ocean should be ______ to install an OTEC power plant.
40 oC
50 oC
20 oC
30 oC
20 0C
A man started to dig the ground. As he kept digging deeper and deeper he reached a level where all the spaces between particles of soil and gaps between rocks were filled with water. The upper limit of this layer is called
A wall has two layers A and B. each made of different material. Both the layers have the same thickness. The thermal conductivity for A is twice that of B. Under steady state, the temperature difference across the whole wall is 360C .Then the temperature difference across the layer A is.