A dephlegmator is a_____________________?

Related Mcqs:

1. ‘Fouling factor’ used in the design of a multipass shell and tube heat exchanger is a_____________________?

   A. Non-dimensional factor
   B. Factor of safety
   C. Conversion factor for individual film heat transfer co-efficient to overall heat transfer coefficient
   D. None of these

2. LMTD can’t be used as such without a correction factor for the_________________?

   A. Multipass heat exchanger
   B. Baffled heat exchanger
   C. Condensation of mixed vapour in a condenser
   D. All A. B. and C.

3. Heat flux increases with temperature drop beyond the Leiden frost point in the plot of heat flux vs. temperature drop for a boiling liquid, because___________________?

   A. Convection becomes important
   B. Conduction becomes important
   C. Radiation becomes important
   D. Sub-cooled boiling occurs

4. _____________ heat exchanger is used for chilling oil to be dewaxed?

   A. U-tube
   B. Double pipe
   C. Fixed tube
   D. Floating head

5. Water is normally used as a coolant in the heat exchange equipments mainly because of its___________________?

   A. Abundance & high heat capacity
   B. Low density
   C. Low viscosity
   D. High fluidity

6. In Biot number, the characteristic length used is the ratio of the _______________ of the solid?

   A. Volume to surface area
   B. Perimeter to surface area
   C. Surface area to volume
   D. Surface area to perimeter

7. What is the logarithmic mean of r1 and r2 ?

   A. (r1 – r2)/ln(r1/r2)
   B. (r1 – r2)/ln(r2/r1)
   C. (r2 – r1)/ln(r1/r2)
   D. (r1 – r2)/-ln(r1/r2)

8. In forced convection, the heat transfer depends on _______________?

   A. Re, Pr
   B. Re, Gr
   C. Mainly Gr
   D. Re only

9. When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids ?

   A. At high fluid velocity
   B. At low velocity
   C. When fluid flows past a smooth surface
   D. None of these

10. Sensible heat of hot industrial flue gases cannot be recovered by a/an________________?

    A. Economiser
    B. Regenerator
    C. Ceramic recuperator
    D. None of these