In convection heat transfer from hot flue gases to water tube, even though flow may be turbulent, a laminar flow region (boundary layer of film) exists close to the tube. The heat transfer through this film takes place by___________________?

Related Mcqs:

1. In regenerator type heat exchanger, heat transfer takes place by___________________?

   A. direct mixing of hot and cold fluids
   B. a complete separation between hot and cold fluids
   C. flow of hot and cold fluids alternately over a surface
   D. generation of heat again and again
   E. indirect transfer

2. Heat transfer in liquid and gases takes place by_____________________?

   A. conduction
   B. convection
   C. radiation
   D. conduction and convection
   E. convection and radiation

3. When heat is transferred form hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by __________________?

   A. conduction
   B. convection
   C. radiation
   D. conduction and convection
   E. convection and radiation

4. When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by ___________________?

   A. conduction
   B. convection
   C. radiation
   D. conduction and convection
   E. convection and radiation

5. Heat is transferred by all three modes of transfer, viz, conduction, convection and radiation in _________________?

   A. electric heater
   B. steam condenser
   C. melting of ice
   D. refrigerator condenser coils
   E. boiler

6. A non-dimensional number generally associated with natural convection heat transfer is________________?

   A. Grashoff number
   B. Nusselt number
   C. Weber number
   D. Prandtl number
   E. Reynold number

7. The concept of overall coefficient of heat transfer is used in case of heat transfer by________________?

   A. conduction
   B. convection
   C. radiation
   D. conduction and convection
   E. convection and radiation

8. LMTD in case of counter flow heat exchanger as compared-to parallel flow heat exchanger is _________________?

   A. higher
   B. lower
   C. same
   D. depends on the area of heat exchanger
   E. depends on temperature conditions

9. Heat transfer takes place as per ________________?

   A. zeroth law of thermodynamics
   B. first law of thermodynamic
   C. second law of the thermodynamics
   D. Kirchoff’s law E. Stefan’s law

10. When heat is Transferred by molecular collision, it is referred to as heat transfer by __________________?

    A. conduction
    B. convection
    C. radiation
    D. scattering
    E. convection and radiation