chemical engineering heat transfer chemical engineering MCQs – Page 17

Practise multiple-choice questions from chemical engineering heat transfer chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering heat transfer chemical engineering Mcqs
321. If the baffle spacing in a shell and tube heat exchanger increases, then the Reynolds number of the shell side fluid_________________?
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A. Remains unchanged

B. Increases

C. Increases or decreases depending on number of shell passes

D. Decreases
322. Boiling point elevation of an ideal solution_______________?
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A. Increases rapidly with temperature rise

B. Decreases rapidly with temperature rise

C. In independent of pressure

D. Both B. and C.

323. Heat produced when a steady state current, I passes through an electrical conductor having resistance, R is___________________?
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A. IR

B. IR2

C. I2R

D. I2R2

324. Small scale evaporation is done in a_________________?
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A. Steam jacketed kettle

B. Multiple effect evaporator

C. Heat exchanger

D. Condenser

325. Overall thermal resistance for conductive heat transfer through a series of flat resistances is equal to the____________________?
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A. Sum of all resistances

B. Average of all resistances

C. Maximum resistance in the series

D. Minimum resistance presents in the series

326. Absorptivity of a perfect black body is unity. Which of the following has maximum absorptivity ?
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A. Aluminium foil

B. Refractory bricks

C. Coke breeze

D. Iron plate

327. Pick out the wrong statement ?
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A. The amount of heat involved in the condensation or vaporisation of 1 kg of a fluid is the same

B. Propagation velocity for travel of heat radiation through vacuum is equal to the velocity of the light

C. Heat transfer by radiation cannot occur across an absolute volume

D. In case of a shell and tube heat exchanger, the pressure drop through the shell is proportional to the number of times the fluid crosses the bundle between baffles

328. For a fluid flowing in an annulus space, the wetted perimeter for heat transfer and pressure drop are__________________?
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A. Same

B. Different

C. Linearly related

D. Never different

329. Which of the following accessories is provided in the vapor line of an evaporator for removing the entrained liquid ?
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A. Bleed point

B. Catchall

C. Baffle

D. Vent

330. _____________ equation relates the thermal conductivity of a solid to its temperature ?
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A. Antoine

B. 217;s

C. Lees

D. Kistyakowsky

331. The statement that maximum wavelength of radiation is inversely proportional to the temperature is ______________ law?
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A. Stefan-Boltzmanns

B. None of these

C. Wiens displacement

D. Plancks

332. In a boiling curve, the peak heat flux is called the _____________ point?
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A. Nusselt

B. Burnout

C. Leidenfrost

D. Boiling

333. The purpose of providing a catchall in the vapor line of an evaporator is to__________________?
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A. Create vacuum

B. Regulate the vapor flow

C. Arrest the entrained liquid

D. Vent the non-condensable gases

334. Unsteady state heat conduction occurs, when_______________?
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A. Temperature distribution is dependent on time

B. Heat flows in one direction only

C. Three dimensional heat flow is concerned

D. Temperature distribution is independent of time

335. Which of the following has the highest thermal conductivity ?
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A. Silver

B. Water

C. Air

D. Brick

336. In regenerative air preheater (as practised in heating of coke ovens), the heat is transferred_________________?
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A. By heating an intermediate material (like chequor bricks) and then heating the air from this

B. By direct contact of hot flue gas with air

C. material</strong>

D. None of these

E. Through a metallic wall

337. Heat flux through several resistances in series in analogous to the current flowing through several_____________________?
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A. Capacitors in series

B. Resistances in series

C. Resistances in parallel

D. None of these

338. Arithmetic mean area can be used in heat transfer problem to calculate the heat flow by conduction through a cylinder which is ____________________?
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A. Thin walled having the value of Ao Ai/< 2

B. Thick walled

C. Having the value of Ao/Ai > 2

D. Both B. and C.

339. With increase in porosity, the thermal conductivity of a solid substance__________________?
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A. Decreases

B. May increase or decrease; depends on the solid

C. Increases

D. Remains unchanged

340. Choose the most important factor on which the heat conducted through a wall in a unit time will depend on ?
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A. Material of the wall

B. Temperature difference between the two surfaces of the wall

C. Area of the wall perpendicular to heat flow

D. Thickness of the wall