Q. The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a refrigerator (COP)R and the co-efficient of performance as a heat pump (COP)HP are

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Q. Crystal size in a continuous crystalliser depends upon the

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Q. Heat waves

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Q. Air is best heated with steam in a heat exchanger of

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Q. Which of the following is generally considered as opaque surface towards radiations?

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Q. Black liquor generated during paper manufacture is concentrated in a

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Q. When vaporisation takes place directly at the heating surface, it is called

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Q. Steam consumption in kg/hr in case of an evaporator is given by (where, C & E are capacity the economy of the evaporator respectively)

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Q. With increase in temperature, the thermal conductivity of non-metallic amorphous solids

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Q. Fourier's law applies to the heat transfer by

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Q. The equivalent diameter for pressure drop is __________ that for heat transfer.

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Q. Controlling heat transfer film co-efficient is the one, which offers __________ resistance to heat transfer.

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Q. The heat flux (from outside to inside) across an insulating wall with thermal conductivity, K= 0.04 W/m.°K and thickness 0.16m is 10 W/m². The temperature of the inside wall is - 5°C. The outside wall temperature is

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Q. Thermal conductivity of a conducting solid material depends upon its

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Q. Pick out the wrong statement.

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Q. Shell side pressure drop in a shell and tube heat exchanger does not depend upon the

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Q. In the equation Q = UAΔt; Δt is

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Q. With increase in porosity, the thermal conductivity of a solid substance

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Q. For an ideal black body

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Q. In Joule's experiment, an insulated container contains 20 kg of water initially at 25°C. It is stirred by an agitator, which is made to turn by a slowly falling body weighing 40 kg through a height of 4 m. The process is repeated 500 times. The acceleration due to gravity is 9.8 ms⁻². Neglecting the heat capacity of agitator, the temperature of water (in °C) is

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