The dimension of surface tension is :

Refer to figure, the absolute pressure of gas $$A$$ in the bulb is

In certain $$HE,$$ both the fluids have identical mass flow rate-specific heat product. The hot fluid enters at $${76^ \circ }C$$ and leaves at $${47^ \circ }C$$ and the cold fluid entering at $${28^ \circ }C$$ leave at $${55^ \circ }C$$. The effectiveness of the heat exchanger $$(HE)$$ is

In a certain double pipe heat exchanger hot water flows at a rate of $$50,000$$ $$kg/h$$ and gets cooled from $${95^ \circ }C$$ to $${65^ \circ }C$$. At the same time $$50,000$$ $$kg/h$$ of cooling water at $${30^ \circ }C$$ enters the heat exchanger. The flow conditions are such that the overall heat transfer coefficient remains constant at $$2270$$ $$W/{m^2}K$$. Calculate the heat transfer area required, assuming the two streams are in parallel flow, and for both the streams $${C_p} = 4.2\,\,kJ/kg\,\,K$$