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.

View solution

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

View solution

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.

View solution

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

View solution

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

View solution

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

View solution

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

View solution

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

View solution

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

View solution

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.

View solution

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

View solution

Q. Radiation dryers use _____

View solution

Q. Which of the following sentences is true?

View solution

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

View solution

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

View solution

Q. Which of the following is an advantage of using pumps as heat transfer equipment?

View solution

Q. External heat exchangers are gaining popularity as they’ve several advantages over conventional methods. Still, there is a major drawback. Which among the following is it?

View solution

Q. Contamination takes place to high extend in Plate heat exchangers.

View solution

Q. Statement 1: In coiled heat exchanger, the coils can be present inside and outside the vessel.
Statement 2: The coils can have either hot/cold fluid present inside them or even electrical coils can be present.

View solution

Q. Which of the following is a parameter to be checked before choosing the shape of the pitch in heat exchangers?

View solution