Q. Conduction occurs in the buffer zone for a fluid flowing through a heated pipe, only when Prandtl number is

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Q. The average heat transfer co-efficient over the entire length of the plate (ha) and the local heat transfer co-efficient (hL), in case of heat transfer over a flat plate in lminar zone is related as

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Q. Maximum heat transfer rate is achieved in __________ flow.

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Q. Wavelength corresponding to the maximum energy is inversely proportional to the absolute temperature. This is __________ law.

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Q. Three material A, B and C of equal thick-nes and of thermal conductivity of 20, 40 & 60 kcal/hr. m. °C respectively are joined together. The temperature outside of A and C are 30°C and 100°C respectively. The interface between B and C will be at a temperature of __________ °C.

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Q. The unit of conductance in SI unit is

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Q. In a shell and tube heat exchanger, square pitch compared to triangular pitch

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Q. Which of the following has maximum thermal conductivity ?

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Q. A wall has two layers of materials A and B; each made of a different material. Both the layers have the same thickness. The thermal conductivity of materialA is twice that of B. Under the equilibrium, the temperature difference across the wall is 36°C. The temperature difference across the layer A is __________ °C.

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Q. The film co-efficient between condensing vapour and metal wall increases with

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Q. A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co-efficient for air will vary in the ratio of

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Q. Heat sensitive materials can be concentrated in an evaporator employing

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Q. A concentric double pipe heat exchanger as compared to the shell and tube heat exchanger for the same heat load requires

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Q. In a shell and tube heat exchanger, floating head is used for

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Q. Steam trap is used to

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Q. Kirchoff's law is applicable to

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Q. In a forward feed multiple effect evaporator, the pressure is

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Q. In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will

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Q. Which of the following situations can be approximated to a steady state heat transfer system ?

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Q. Sensible heat absorbed by 1 lb of water when it is heated from 32 to 212°F may be around __________ BTU.

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