A. Coated
B. Oily
C. Glazed & polished
D. Smooth
Related Mcqs:
- The heat transfer co-efficient in film type condensation is _______________ that for dropwise condensation?
A. Greater than
B. Lower than
C. Is same as
D. Half - Dropwise condensation is promoted on a/an ______________ surface?
A. Glazed
B. Oily
C. Coated
D. Smooth - Dropwise condensation occurs on ______________ surfaces?
A. Clean and dirt free
B. Smooth clean
C. Contaminated cooling
D. Polished - For condensation of pure vapors, if the heat transfer co-efficients in filmwise and drop-wise condensation are respectively hf and hd, then__________________?
A. hf = hd
B. hf > hd
C. hf < hd
D. hf could be greater or smaller than hd - The local surface conductance for laminar film condensation on vertical surface is (where, t = film thickness) _________________?
A. ∝ t
B. ∝ 1/t
C. ∝ √t
D. Independent of ‘t’ - The film thickness for laminar film condensation on vertical surface _____________ from top to bottom?
A. Cumulatively increases
B. Cumulatively decreases
C. Remain constant
D. And the surface conductance increase - Film condensation is promoted on a/an _______________________ surface?
A. Oily
B. Coated
C. Clean & smooth
D. Dirty - In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will___________________?
A. Increase
B. Decrease
C. Remain unchanged
D. Either increase or decrease; depends on the coolant flow rate - Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2.°C. Condensation of vapor is carried out inside the tube in a shell and tube heat exchanger, when the_________________?
A. Higher condensing film co-efficient is desired
B. Condensate is corrosive in nature
C. Lower pressure drop through the exchanger is desired
D. Temperature of the incoming vapor is very high - If air (a non-condensing gas) is present in a condensing vapor stream, it will ______________ the condensation rate of vapor?
A. Increase
B. Decrease
C. Not affect
D. Increase the condensing film co-efficient as well as
