Chemical Heat Transfer

Extended heat transfer surface like fins are used to increase the heat transfer rate. Fin efficiency is defined as the ratio of heat transferred across the fin surface to the theoretical heat transfer across an equal area held at the________________?

A. Surrounding temperature
B. Average temperature of the fin
C. Temperature of the fin end
D. Constant temperature equal to that of the base

Read More Details about this Mcq:

The actual temperature drop across the heating surface in an evaporator depends on the_________________?

A. Feed
B. Depth of liquid over heating surface
C. Pressure difference between steam chest and vapour space
D. All A., B. and C.

Read More Details about this Mcq:

Heat flux is the time rate of heat transfer per unit_______________?

A. Length
B. Area
C. Volume
D. None of these

Read More Details about this Mcq:

The steam ejector is used to__________________?

A. Remove condensate from the steam pipelines
B. Create vacuum
C. Superheat the steam
D. None of these

Read More Details about this Mcq:

Steam is to be condensed in a shell and tube heat exchanger, 5 m long with a shell diameter of 1 m. Cooling water is to be used for removing the heat. Heat transfer co-efficient for the cooling water, whether on shell side or tube side is the same. The best arrangement is_____________?

A. Vertical heat exchanger with steam on tube side
B. Vertical heat exchanger with steam on shell side
C. Horizontal heat exchanger with steam on tube side
D. Horizontal heat exchanger with steam on shell side

Read More Details about this Mcq:

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

A. Gases
B. Solids
C. Liquids
D. Both B. and C.

Read More Details about this Mcq:

Fourier’s law of heat conduction applies to _____________ surfaces?

A. Isothermal
B. Non-isothermal
C. Both A. and B.
D. Neither A. and B.

Read More Details about this Mcq:

200 kg of solids (on dry basis) is subjected to a drying process for a period of 5000 seconds. The drying occurs in the constant rate period with the drying rate as, Nc = 0.5 × 10-3 kg/m2.s. The initial moisture content of the solid is 0.2 kg moisture/kg dry solid. The interfacial area available for drying is 4 m2/1000 kg of dry solid. The moisture content at the end of the drying period is (in kg moisture/kg dry solid)?

A. 0.5
B. 0.05
C. 0.1
D. 0.15

Read More Details about this Mcq:

Harmonic mean temperature difference is given by_________________?

A. √(ΔT1 . ΔT2)
B. 2 (ΔT1 . ΔT2)/(ΔT1 + ΔT2)
C. 2 (ΔT1 . ΔT2)/(ΔT1 – ΔT2)
D. (ΔT1 – ΔT2)/(ΔT1 . ΔT2)

Read More Details about this Mcq:

If average heat transfer co-efficient is ha and the local coefficient at the end of the plate is hl then in case of heat transfer to a fluid flowing over a flat plate, heated over its entire length________________?

A. ha = hl
B. ha = 2hl
C. ha = 0.5 hl
D. ha = 0.75 hl

Read More Details about this Mcq: