Q. Find heat transfer in an agitated jacketed vessel if Nᵣₑᵢ is 1.5 * 105 and Nₚᵣ is 20.

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Q. Which of the following is NOT a real dimensionless number?

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Q. Statement 1: Nₚᵣ= (Cₚm)/kl
Statement 2: Stanton number is a product of Nᵣₑ and Nₚᵣ.

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Q. Statement 1: G is known as the mass flux and it is the product of density and velocity.
Statement 2: Grashof number is associated with forced convection.

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Q. Фᵥ is generally taken as 1 in food processing as generally very high wall temperatures aren’t reached and hence (µ/µw) * 0.14 is 1 as there isn’t much difference in µ and µw.

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Q. Statement 1: Sieder-Tate and Dittus-boelter equations imply only to laminar flow conditions.
Statement 2: Under laminar conditions, the same equation applies both to Newtonian and Non-Newtonian fluids.

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Q. Dittus-boelter equation is applicable for fluids with phase change.

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Q. Statement 1: Radiation is the transfer of heat by electromagnetic waves.
Statement 2: When heat is radiated from a hot source, the amount of heat received by the body depends on the nature of the body.

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Q. Statement 1: Radiation needs a medium to travel.
Statement 2: Thermal radiation takes place at a certain temperature for every body.

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Q. Statement 1: Radiation is NOT heat.
Statement 2: Maximum value of absorptivity is 1.

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Q. The emission of radiation by any body is independent of the radiation by any body next to it.

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Q. A food industry keeps food cool in a very crude manner, by radiation. It paints its walls white and not black, because of _____

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Q. Which of the following reason does NOT affect radiation between two parallel bodies?

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Q. Freezer is at -18 °C. Will will be Radiative heat transfer if meat is at 298k, its emissivity is 0.82 and average area is 0.045m².
Either use Stefan Boltzmann law or take hᵣ (radiative heat transfer co-efficient) as 0.227.

ε = ( Tₐᵥ/100 )³

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Q. Statement 1: Radiation dryers are used to dry grains and reduce their moisture content before storage.
Statement 2: Baking ovens are used both for making the dough and after that’s made, making biscuits by cutting them and baking them further. This entire process uses radiation.

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Q. In deep freezers, the walls absorb heat from food materials by _____ and keep them cool.

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Q. Radiation dryers use _____

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Q. Which of the following sentences is true?

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Q. If _______ heating has higher heat transfer rates than _______ heating, then why is ________ difficult to be used.

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Q. In a jacketed vessel, the only way to increase the heat transfer rates is to increase the temperature difference.

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