Heat Transfer (Chemical Perspective) – Multiple Choice Questions (MCQs)

1. 85. What is 'insulation'?

   • A. Material used to increase heat transfer
   • B. Material used to reduce heat transfer
   • C. Material used to conduct electricity
   • D. Material used for structural support

2. 86. What is the purpose of 'fins' on heat transfer surfaces?

   • A. To decrease the surface area for heat transfer
   • B. To increase the surface area for heat transfer
   • C. To reduce fluid flow
   • D. To increase pressure drop

3. 87. What is 'natural convection'?

   • A. Fluid movement due to density differences arising from temperature variations
   • B. Fluid movement forced by pumps or fans
   • C. Heat transfer through direct contact
   • D. Heat transfer by electromagnetic waves

4. 88. What is 'boiling heat transfer'?

   • A. Heat transfer during a phase change from liquid to vapor
   • B. Heat transfer during a phase change from solid to liquid
   • C. Heat transfer in solids
   • D. Heat transfer in gases

5. 89. What is 'condensation heat transfer'?

   • A. Heat transfer during a phase change from vapor to liquid
   • B. Heat transfer during a phase change from liquid to vapor
   • C. Heat transfer in solids
   • D. Heat transfer in gases

6. 90. What is 'nucleate boiling'?

   • A. Boiling characterized by the formation and growth of bubbles at nucleation sites on the heating surface
   • B. Boiling without bubble formation
   • C. Boiling on a completely smooth surface
   • D. Boiling that occurs at very low heat fluxes

7. 91. What is a 'reboiler' in a distillation column?

   • A. A heat exchanger that provides heat to vaporize part of the liquid mixture
   • B. A heat exchanger that removes heat to condense vapor
   • C. A device for mixing liquids
   • D. A device for separating solids

8. 92. What is a 'condenser' in a distillation column?

   • A. A heat exchanger that provides heat to vaporize liquid
   • B. A heat exchanger that removes heat to condense vapor
   • C. A device for mixing gases
   • D. A device for separating liquids

9. 93. What is 'effectiveness' (ε) of a heat exchanger?

   • A. The ratio of actual heat transfer rate to the maximum possible heat transfer rate
   • B. The overall heat transfer coefficient
   • C. The LMTD
   • D. The fluid flow rate

10. 94. What is the 'Number of Transfer Units' (NTU) in heat exchanger design?

    • A. A dimensionless parameter indicating the size of the heat exchanger
    • B. The efficiency of the heat exchanger
    • C. The LMTD
    • D. The heat transfer rate

11. 95. What is 'radiation heat transfer'?

    • A. Transfer of energy by electromagnetic waves
    • B. Transfer of energy by direct contact
    • C. Transfer of energy by fluid motion
    • D. Transfer of energy through a vacuum

12. 96. What is the 'view factor' (F_ij) in radiation heat transfer?

    • A. A geometric factor that describes the fraction of radiation leaving surface 'i' that strikes surface 'j'
    • B. The emissivity of a surface
    • C. The temperature of a surface
    • D. The area of a surface