Dropwise condensation of steam on cooling surface is promoted

1.	Dropwise condensation of steam on cooling surface is promoted
A.	an oily surface.
B.	when both the steam and the tube are clean.
C.	only in presence of air.
D.	none of these.
Answer» B. when both the steam and the tube are clean.

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Dropwise condensation of steam on cooling surface is promoted

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